compileroptions.cmake: disabled -Wthread-safety-negative and -Wthread-safety-beta Clang warnings with libc++

Author: firewave

cmake/compileroptions.cmake

@@ -165,6 +165,12 @@ elseif(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     # this is reported even when it is unnecessary i.e. -Wswitch-enum warnings have been mitigated
     add_compile_options_safe(-Wno-switch-default)
 
+    if(USE_LIBCXX)
+        # these are experimental warnings which might produce false positives
+        add_compile_options_safe(-Wno-thread-safety-negative)
+        add_compile_options_safe(-Wno-thread-safety-beta)
+    endif()
+
     # warnings we are currently not interested in
     add_compile_options(-Wno-four-char-constants)
     add_compile_options(-Wno-weak-vtables)