This PR fixes warning "Compiler lib dir != compiler-rt lib dir"
There is a check in compiler-rt/test/lit.common.cfg.py which detects
runtime dir using target_cflags.
If we set target_flags only, the test will complain as below:
The persistent from #111498, but I don't see anything wrong.
```
cmake -GNinja -DCMAKE_BUILD_TYPE=Release -DCMAKE_DISABLE_PRECOMPILE_HEADERS=ON -DLLVM_CCACHE_BUILD=ON -DLLVM_ENABLE_ASSERTIONS=OFF '-DLLVM_ENABLE_PROJECTS='\''clang;lld'\''' '-DLLVM_ENABLE_RUNTIMES='\''compiler-rt;libunwind;libcxx;libcxxabi'\''' -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../../llvm-project/llvm
ninja check-compiler-rt
```
```
-- Installing: runtimes/runtimes-bins/compiler-rt/lib/tsan/libcxx_tsan_x86_64/lib/libc++.modules.json
[3235/3236] Running compiler_rt regression tests
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:244: warning: Compiler lib dir != compiler-rt lib dir
Compiler libdir: "lib/clang/23/lib/x86_64-unknown-linux-gnu"
compiler-rt libdir: "lib/clang/23/lib/i386-unknown-linux-gnu"
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:255: warning: COMPILER_RT_TEST_STANDALONE_BUILD_LIBS=ON, but this test suite does not support testing the just-built runtime libraries when the test compiler is configured to use different runtime libraries. Either modify this test suite to support this test configuration, or set COMPILER_RT_TEST_STANDALONE_BUILD_LIBS=OFF to test the runtime libraries included in the compiler instead.
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:266: note: Testing using libraries in "./lib/../lib/clang/23/lib/i386-unknown-linux-gnu"
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:244: warning: Compiler lib dir != compiler-rt lib dir
Compiler libdir: "lib/clang/23/lib/x86_64-unknown-linux-gnu"
compiler-rt libdir: "lib/clang/23/lib/i386-unknown-linux-gnu"
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:255: warning: COMPILER_RT_TEST_STANDALONE_BUILD_LIBS=ON, but this test suite does not support testing the just-built runtime libraries when the test compiler is configured to use different runtime libraries. Either modify this test suite to support this test configuration, or set COMPILER_RT_TEST_STANDALONE_BUILD_LIBS=OFF to test the runtime libraries included in the compiler instead.
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:266: note: Testing using libraries in "./lib/../lib/clang/23/lib/i386-unknown-linux-gnu"
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:244: warning: Compiler lib dir != compiler-rt lib dir
Compiler libdir: "lib/clang/23/lib/x86_64-unknown-linux-gnu"
compiler-rt libdir: "lib/clang/23/lib/i386-unknown-linux-gnu"
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:255: warning: COMPILER_RT_TEST_STANDALONE_BUILD_LIBS=ON, but this test suite does not support testing the just-built runtime libraries when the test compiler is configured to use different runtime libraries. Either modify this test suite to support this test configuration, or set COMPILER_RT_TEST_STANDALONE_BUILD_LIBS=OFF to test the runtime libraries included in the compiler instead.
llvm-lit: llvm-project/compiler-rt/test/lit.common.cfg.py:266: note: Testing using libraries in "./lib/../lib/clang/23/lib/i386-unknown-linux-gnu"
```
For libfuzzer there should be no difference, as it already applies
target_cflags.
4b44e2039c