[clang] [llvm] [OpenACC] Switch Clang to use the Flang 'appertainment' rules for cla… (PR #135372)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64-flang-aix` running on `ppc64-flang-aix-test` while building `clang,llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/201/builds/4199

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
4958.728 [4409/10/3689] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaHLSL.cpp.o
4961.089 [4408/10/3690] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaM68k.cpp.o
4963.774 [4407/10/3691] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaLoongArch.cpp.o
4964.682 [4406/10/3692] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaMSP430.cpp.o
4967.684 [4405/10/3693] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaMIPS.cpp.o
4968.951 [4404/10/3694] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaLambda.cpp.o
4971.573 [4403/10/3695] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaInit.cpp.o
4971.888 [4402/10/3696] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaNVPTX.cpp.o
4974.503 [4401/10/3697] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaModule.cpp.o
4977.282 [4400/10/3698] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACCClauseAppertainment.cpp.o
FAILED: tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACCClauseAppertainment.cpp.o 
/home/llvm/llvm-external-buildbots/clang.19.1.2/bin/clang++ -DCLANG_EXPORTS -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_LARGE_FILE_API -D_XOPEN_SOURCE=700 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/tools/clang/lib/Sema -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/clang/lib/Sema -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/clang/include -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/tools/clang/include -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/include -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/llvm/include -mcmodel=large -fPIC -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -pthread -MD -MT tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACCClauseAppertainment.cpp.o -MF tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACCClauseAppertainment.cpp.o.d -o tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACCClauseAppertainment.cpp.o -c /home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/clang/lib/Sema/SemaOpenACCClauseAppertainment.cpp
/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/clang/lib/Sema/SemaOpenACCClauseAppertainment.cpp:73:10: fatal error: 'llvm/Frontend/OpenACC/ACC.inc' file not found
   73 | #include "llvm/Frontend/OpenACC/ACC.inc"
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
4978.350 [4400/9/3699] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACCAtomic.cpp.o
4981.133 [4400/8/3700] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaLookup.cpp.o
4983.768 [4400/7/3701] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaObjCProperty.cpp.o
4984.497 [4400/6/3702] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACC.cpp.o
4984.499 [4400/5/3703] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenACCClause.cpp.o
4984.909 [4400/4/3704] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaObjC.cpp.o
4987.278 [4400/3/3705] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaOpenCL.cpp.o
4990.268 [4400/2/3706] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExprCXX.cpp.o
5019.342 [4400/1/3707] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/135372