[llvm] Revert "RuntimeLibcalls: Use get_host_tool_path for executables used … (PR #159488)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-lld-multistage-test` running on `ppc64le-lld-multistage-test` while building `llvm` at step 12 "build-stage2-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/168/builds/16208

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 12 (build-stage2-unified-tree) failure: build (failure) (timed out)
...
913.238 [128/12/6564] Building CXX object tools/clang/unittests/CMakeFiles/AllClangUnitTests.dir/Tooling/RecursiveASTVisitorTests/CallbacksBinaryOperator.cpp.o
920.386 [128/11/6565] Building CXX object tools/clang/unittests/CMakeFiles/AllClangUnitTests.dir/Tooling/RecursiveASTVisitorTests/CallbacksLeaf.cpp.o
935.091 [128/10/6566] Building CXX object tools/clang/unittests/CMakeFiles/AllClangUnitTests.dir/Tooling/RecursiveASTVisitorTests/CallbacksCompoundAssignOperator.cpp.o
939.448 [128/9/6567] Building CXX object lib/Target/AMDGPU/CMakeFiles/LLVMAMDGPUCodeGen.dir/AMDGPUTargetMachine.cpp.o
940.274 [128/8/6568] Building CXX object tools/clang/unittests/CMakeFiles/AllClangUnitTests.dir/ASTMatchers/ASTMatchersNodeTest.cpp.o
952.164 [128/7/6569] Building CXX object lib/Target/AMDGPU/MCTargetDesc/CMakeFiles/LLVMAMDGPUDesc.dir/AMDGPUMCTargetDesc.cpp.o
1019.422 [128/6/6570] Building CXX object tools/clang/unittests/CMakeFiles/AllClangUnitTests.dir/ASTMatchers/ASTMatchersNarrowingTest.cpp.o
1120.220 [128/5/6571] Building CXX object lib/Target/AMDGPU/AsmParser/CMakeFiles/LLVMAMDGPUAsmParser.dir/AMDGPUAsmParser.cpp.o
1317.535 [128/4/6572] Building CXX object tools/clang/unittests/CMakeFiles/AllClangUnitTests.dir/AST/ASTImporterTest.cpp.o
1661.170 [128/3/6573] Building CXX object tools/clang/unittests/CMakeFiles/AllClangUnitTests.dir/ASTMatchers/ASTMatchersTraversalTest.cpp.o
command timed out: 1200 seconds without output running [b'ninja'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2861.627955

```

</details>

https://github.com/llvm/llvm-project/pull/159488