[clang] [LLVMABI] Introduce the QualTypeMapper (PR #174634)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-flang-rhel-clang` running on `ppc64le-flang-rhel-test` while building `clang` at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/45101

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

```
Step 6 (test-build-unified-tree-check-flang) failure: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
...
16.540 [3/8/30] Building CXX object tools/flang/unittests/Frontend/CMakeFiles/FlangFrontendTests.dir/FrontendActionTest.cpp.o
16.587 [2/7/32] Building CXX object tools/flang/unittests/Optimizer/CMakeFiles/FlangOptimizerTests.dir/FortranVariableTest.cpp.o
16.661 [2/6/33] Building CXX object tools/flang/unittests/Optimizer/CMakeFiles/FlangOptimizerTests.dir/RTBuilder.cpp.o
16.876 [1/6/34] Linking CXX shared module lib/flangFeatureList.so
17.000 [1/5/35] Linking CXX shared module lib/flangOmpReport.so
17.045 [1/4/36] Linking CXX shared module lib/flangPrintFunctionNames.so
17.403 [1/3/37] Linking CXX executable tools/flang/unittests/Common/FlangCommonTests
23.625 [1/2/38] Linking CXX executable tools/flang/unittests/Optimizer/FlangOptimizerTests
33.545 [1/1/39] Linking CXX executable tools/flang/unittests/Frontend/FlangFrontendTests
33.546 [0/1/39] Running the Flang regression tests
command timed out: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1234.433681

```

</details>

https://github.com/llvm/llvm-project/pull/174634