Remove unsupported case "AtomicOps" from AIX test list.

Summary: The test-suite case `AtomicOps.c` is unsupported on 32-bit AIX. It fails at link stage and complains about undefined symbol `__sync_fetch_and_add_8` and `__sync_fetch_and_sub_8`. Compilers on the platform are consistent in not supporting these built-ins. An implementation of them would need to use locks.

Reviewers: hubert.reinterpretcast, daltenty

Reviewed By: hubert.reinterpretcast, daltenty

Subscribers: mgorny, jfb

Differential Revision: https://reviews.llvm.org/D82052

Author: steven-wan-yu

CMakeLists.txt

@@ -233,6 +233,7 @@ endif()
 #     The outputs can be compared to gcc.
 #     The outputs match the reference outputs.
 if(ARCH STREQUAL "PowerPC")
+  check_symbol_exists(_LP64 "" PPC_IS_PPC64_ENABLED)
   add_definitions(-ffp-contract=off)
 endif()
 

SingleSource/UnitTests/CMakeLists.txt

@@ -11,6 +11,9 @@ if(TARGET_OS STREQUAL "Darwin")
 endif()
 
 file(GLOB Source RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} *.c *.cpp)
+if(TARGET_OS STREQUAL "AIX" AND ARCH STREQUAL "PowerPC" AND NOT PPC_IS_PPC64_ENABLED) 
+  list(REMOVE_ITEM Source AtomicOps.c)
+endif()
 if(TARGET_OS STREQUAL "Darwin")
   list(REMOVE_ITEM Source 2007-04-25-weak.c)
   if(ARCH STREQUAL "PowerPC")