[OpenMP] Add CMake option to disable `libarcher` support

[jhuber6]

Summary

The support for libarcher can sometimes cause problems when running
tests or building. We want an option to turn this off when we are not
directly testing libarcher.

[jplehr]

LGTM

[protze.joachim]

Just of curiosity, what kind of issues do you experience? Is this something that should/can be fixed?

openmp/tools/archer/CMakeLists.txt

 # //===----------------------------------------------------------------------===//
 # //
 # // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # // See https://llvm.org/LICENSE.txt for details.
 # // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 # //
 # //===----------------------------------------------------------------------===//
   
-  
-
-if(LIBOMP_OMPT_SUPPORT)
+set(LIBOMP_ARCHER_SUPPORT TRUE CACHE BOOL "Build libomp with archer support")
+if(LIBOMP_OMPT_SUPPORT AND LIBOMP_ARCHER_SUPPORT)
   include_directories(${LIBOMP_INCLUDE_DIR})
 
   add_library(archer SHARED ompt-tsan.cpp)
   target_link_libraries(archer ${CMAKE_DL_LIBS})
   add_library(archer_static STATIC ompt-tsan.cpp)
 
   install(TARGETS archer archer_static
     LIBRARY DESTINATION ${OPENMP_INSTALL_LIBDIR}
     ARCHIVE DESTINATION ${OPENMP_INSTALL_LIBDIR})
 
   add_subdirectory(tests)
 endif()