[compiler-rt] [compiler-rt] Allow running tests without installing first (PR #83088)

[Alexander Richardson via llvm-commits]

arichardson wrote:

> We are also seeing similar problems with our internal builder after this commit:
> 
> ```
> FAILED: projects/compiler-rt/lib/memprof/tests/MemProfUnitTests 
> : && /usr/lib/ccache/g++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wno-unused-parameter -O3 -DNDEBUG -fuse-ld=gold    -resource-dir=/home/jenkins/j/w/workspace/opensource/opensource_build/build/./lib/../lib/clang/19 -Wl,-rpath,/home/jenkins/j/w/workspace/opensource/opensource_build/build/./lib/../lib/clang/19/lib/x86_64-unknown-linux-gnu -pthread <snip>
> g++: error: unrecognized command line option ‘-resource-dir=/home/jenkins/j/w/workspace/opensource/opensource_build/build/./lib/../lib/clang/19’
> ```

That sounds like a either a misconfigured build-bot or a bug in compiler-rt tests using the host compiler instead of the test compiler for this target? This flag will only be added if COMPILER_RT_TEST_COMPILER_ID==Clang, so it definitely should not be added for GCC.

https://github.com/llvm/llvm-project/pull/83088