[cmake][runtimes] Pass variable type for passthrough CMake options

[tambry]

Depends on #198505 and #198506.

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Passing the types affects the handling of PATH cache variables.
The motivating case is setting COMPILER_RT_INSTALL_LIBRARY_DIR without CMAKE_BINARY_DIR getting prepended to it.

[petrhosek]

Looks like this broke our toolchain build with the following error:

CMake Error in /Users/swarming/b/s/w/ir/x/w/llvm-llvm-project/libcxx/src/CMakeLists.txt:
  No known features for CXX compiler

  "Clang"

  version 23.0.0.


CMake Generate step failed.  Build files cannot be regenerated correctly.

You can see the full log here https://logs.chromium.org/logs/fuchsia/buildbucket/cr-buildbucket/8681299599353914865/+/u/clang/build/stdout

Would it be possible to revert?

[tambry]

@petrhosek Revert in #198739. I see nothing obvious in Fuchsia-stage2.cmake that could break in combination with this change.

Would you be able to provide a zipped /Users/swarming/b/s/w/ir/x/w/llvm_build/runtimes/runtimes-x86_64-pc-windows-msvc-bins from the buildbot after failure? Or at least CMakeCache.txt and CMakeFiles/CMakeConfigureLog.yaml? I lack any Windows machines or an appropriate sysroot to reproduce locally. The Fuchsia IDK doesn't seem sufficient.

[tambry]

@petrhosek Ping. I don't want to break your downstream out-of-tree things but I also don't have a way to debug that.