Invoke GetOptionsFromString() in db_stress

`GetOptionsFromString()` is included in `set_options_one_in` because its
current behavior actually involves invoking `PrepareOptions()` on
existing shared option objects that may be in-use by a DB. While this has
known problems like facebook#10374, it is actually used in production and users
are finding these problems before us. To prevent accidental coasting we
should turn on the feature in stress/crash test to ensure we discover
these problems before our users do.

Test Plan:

- Build with TSAN: `$ COMPILE_WITH_TSAN=1 make -j24 db_stress`
- Repro some `GenericRateLimiter` race conditions:

```
$ ./db_stress -rate_limiter_bytes_per_sec=1048576 --set_options_one_in=100 --max_key=1000000
...
WARNING: ThreadSanitizer: data race (pid=3077932)                                                                                                                                                                                                                                                                                                                                                                                                                                   [14/168]  Read of size 4 at 0x7b5800000378 by thread T19:                                                                                                                                                                                                                                                                                                                                                                                                                                               #0 rocksdb::SerializeSingleOptionHelper(void const*, rocksdb::OptionType, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) options/options_helper.cc:480 (db_stress+0x9a858e)
    #1 rocksdb::OptionTypeInfo::Serialize(rocksdb::ConfigOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, void const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) const options/options_helper.cc:1089 (db_stress+0x9a8f94)                                                                                                                                                                       #2 rocksdb::ConfigurableHelper::SerializeOptions(rocksdb::ConfigOptions const&, rocksdb::Configurable const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) options/configurable.cc:575 (db_stress+0x977c13)                                                                                                                                                    facebook#3 rocksdb::Configurable::SerializeOptions(rocksdb::ConfigOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const options/configurable.cc:519 (db_stress+0x978aff)
    facebook#4 rocksdb::Customizable::SerializeOptions(rocksdb::ConfigOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const options/customizable.cc:56 (db_stress+0x98066f)
    facebook#5 rocksdb::Configurable::ToString(rocksdb::ConfigOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const options/configurable.cc:507 (db_stress+0x9767c4)
    facebook#6 rocksdb::Configurable::ToString[abi:cxx11](rocksdb::ConfigOptions const&) const include/rocksdb/configurable.h:181 (db_stress+0x9a94cb)
    facebook#7 rocksdb::OptionTypeInfo::Serialize(rocksdb::ConfigOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, void const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) const options/options_helper.cc:1070 (db_stress+0x9a94cb)
    facebook#8 rocksdb::ConfigurableHelper::SerializeOptions(rocksdb::ConfigOptions const&, rocksdb::Configurable const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) options/configurable.cc:575 (db_stress+0x977c13)
    facebook#9 rocksdb::Configurable::GetOptionString(rocksdb::ConfigOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) const options/configurable.cc:497 (db_stress+0x978a1c)
    facebook#10 rocksdb::GetStringFromDBOptions(rocksdb::ConfigOptions const&, rocksdb::DBOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) options/options_helper.cc:631 (db_stress+0x9a1833)
    facebook#11 rocksdb::PersistRocksDBOptions(rocksdb::ConfigOptions const&, rocksdb::DBOptions const&, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, std::vector<rocksdb::ColumnFamilyOptions, std::allocator<rocksdb::ColumnFamilyOptions> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > co
nst&, rocksdb::FileSystem*) options/options_parser.cc:99 (db_stress+0x9cbc20)
    facebook#12 rocksdb::PersistRocksDBOptions(rocksdb::DBOptions const&, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, std::vector<rocksdb::ColumnFamilyOptions, std::allocator<rocksdb::ColumnFamilyOptions> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, rocksdb::FileSystem*) opt
ions/options_parser.cc:53 (db_stress+0x9ce616)
    facebook#13 rocksdb::DBImpl::WriteOptionsFile(bool, bool) db/db_impl/db_impl.cc:4506 (db_stress+0x5c98e1)
    facebook#14 rocksdb::DBImpl::SetOptions(rocksdb::ColumnFamilyHandle*, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::
basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const&) db/db_impl/db_impl.cc:1152 (db_stress+0x5ca8d8)
    facebook#15 rocksdb::StressTest::SetOptions(rocksdb::ThreadState*) db_stress_tool/db_stress_test_base.cc:577 (db_stress+0x52769c)
    facebook#16 rocksdb::StressTest::OperateDb(rocksdb::ThreadState*) db_stress_tool/db_stress_test_base.cc:714 (db_stress+0x534a7e)
    facebook#17 rocksdb::ThreadBody(void*) db_stress_tool/db_stress_driver.cc:33 (db_stress+0x500b02)
    facebook#18 StartThreadWrapper env/env_posix.cc:461 (db_stress+0x8a0d3f)

  Previous write of size 4 at 0x7b5800000378 by thread T37:
    #0 rocksdb::GenericRateLimiter::Initialize() util/rate_limiter.cc:106 (db_stress+0xb028a0)
    #1 rocksdb::GenericRateLimiter::PrepareOptions(rocksdb::ConfigOptions const&) util/rate_limiter.cc:146 (db_stress+0xb02bb6)
    #2 rocksdb::OptionTypeInfo::Prepare(rocksdb::ConfigOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, void*) const options/options_helper.cc:1408 (db_stress+0x9a0756)
    facebook#3 rocksdb::Configurable::PrepareOptions(rocksdb::ConfigOptions const&) options/configurable.cc:50 (db_stress+0x9757e6)
    facebook#4 rocksdb::DBOptionsConfigurable::ConfigureOptions(rocksdb::ConfigOptions const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std
::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<
std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >*) options/db_options.cc:645 (db_stress+0x98d178)
    facebook#5 rocksdb::Configurable::ConfigureFromMap(rocksdb::ConfigOptions const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<st
d::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cx
x11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >*) options/configurable.cc:143 (db_stress+0x9766f7)
    facebook#6 rocksdb::GetOptionsFromString(rocksdb::ConfigOptions const&, rocksdb::Options const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, rocksdb::Options*) options/options_helper.cc:799 (db_stress+0x9b19cf)
    facebook#7 rocksdb::GetOptionsFromString(rocksdb::Options const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, rocksdb::Options*) options/options_helper.cc:782 (db_stress+0x9b2611)
    facebook#8 rocksdb::StressTest::SetOptions(rocksdb::ThreadState*) db_stress_tool/db_stress_test_base.cc:556 (db_stress+0x527802)
    facebook#9 rocksdb::StressTest::OperateDb(rocksdb::ThreadState*) db_stress_tool/db_stress_test_base.cc:714 (db_stress+0x534a7e)
    facebook#10 rocksdb::ThreadBody(void*) db_stress_tool/db_stress_driver.cc:33 (db_stress+0x500b02)
    facebook#11 StartThreadWrapper env/env_posix.cc:461 (db_stress+0x8a0d3f)
```

db_stress_tool/db_stress_test_base.cc

@@ -548,6 +548,13 @@ void StressTest::PreloadDbAndReopenAsReadOnly(int64_t number_of_keys,
 
 Status StressTest::SetOptions(ThreadState* thread) {
   assert(FLAGS_set_options_one_in > 0);
+  if (thread->rand.Next() % 4 == 0) {
+    // Configuring an options structure can reprepare its member option objects
+    // that are not explicitly changed. Cover that here with 1/4 chance. If this
+    // behavior changes in the future we can remove this.
+    Options copy_options(options_);
+    return GetOptionsFromString(options_, "", &copy_options);
+  }
   std::unordered_map<std::string, std::string> opts;
   std::string name =
       options_index_[thread->rand.Next() % options_index_.size()];