Always emit symbols like _GLOBAL_OFFSET_TABLE_, _PROCEDURE_LINKAGE_TABLE_ and others

[marxin]

I noticed these symbols are always emitted by the Mold linker and the presence of the symbols seems to me pretty hand when it comes to disassembly:

$ cat lib.c
void foo() {
  __builtin_printf("xxx\n");
}
$ gcc lib.c -fPIC -shared -o lib.so -fuse-ld=mold
$ readelf -sW lib.so
...
    67: 00000000000026f0     0 NOTYPE  LOCAL  DEFAULT   19 _DYNAMIC
    68: 00000000000028e8     0 NOTYPE  LOCAL  DEFAULT   21 _GLOBAL_OFFSET_TABLE_
    69: 00000000000015e0     0 NOTYPE  LOCAL  DEFAULT   16 _PROCEDURE_LINKAGE_TABLE_
...
    81: 0000000000000000     0 TLS     LOCAL  DEFAULT    1 _TLS_MODULE_BASE_

On the other hand, the Wild linker does not emit these symbols.

[davidlattimore]

For the most part, I've tried to make Wild match GNU ld as closely as possible. However, it seems reasonable to me to add extra symbols if they're useful for diagnostic purposes, especially given that another linker does it. So adding them sounds good to me

[marxin]

From debugging point of view, it's even more convenient for symbols like this:

   37: 00000000000015f0      0 FUNC    LOCAL  DEFAULT       14 __cxa_finalize$pltgot
   38: 000000000000c4e0      0 OBJECT  LOCAL  DEFAULT       20 __gmon_start__$got
   39: 000000000000c4e8      0 OBJECT  LOCAL  DEFAULT       20 _ITM_deregisterTMCloneTable$got
   40: 000000000000c4f0      0 OBJECT  LOCAL  DEFAULT       20 _ITM_registerTMCloneTable$got
   41: 000000000000c508      0 OBJECT  LOCAL  DEFAULT       20 __cxa_finalize$got
   42: 000000000000c4f8      0 OBJECT  LOCAL  DEFAULT       20 foo$tlsdesc