[libc++] Fix _LIBCPP_EXPORTED_FROM_ABI when visibility annotations are disabled

Fixes a bug where functions would get exported when building with
-fvisibility=hidden and defining _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS. No
visibility annotations should be added in this case.

The new logic for _LIBCPP_EXPORTED_FROM_ABI matches that of the other visibility
annotations around it.

Differential Revision: https://reviews.llvm.org/D55664



git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@349080 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed