[CMake] Re-land llvm#102671 after the flaky test is disabled

Reland llvm#102671 after the other attempted fixes are all flawed in some
build configurations. The previous try for the same commit was breaking
a flaky tests under ASAN which is not marked as unsupported. This fix
should be good to go now.

Fixes AIX bot for DynamicLibraryTests failure.

llvm/unittests/Support/DynamicLibrary/CMakeLists.txt

@@ -17,10 +17,9 @@ set_output_directory(DynamicLibraryLib
 
 add_llvm_unittest(DynamicLibraryTests
  DynamicLibraryTest.cpp
-
- EXPORT_SYMBOLS
  )
 target_link_libraries(DynamicLibraryTests PRIVATE DynamicLibraryLib)
+export_executable_symbols(DynamicLibraryTests)
 
 function(dynlib_add_module NAME)
  add_library(${NAME} MODULE