CMAKE_VISIBILITY_INLINES_HIDDEN is ignored for OBJCXX language
When the OBJCXX language is enabled in CMake 3.16, the CMAKE_VISIBILITY_INLINES_HIDDEN
variable and corresponding target property are ignored for objc++ source files.
This looks to be due to CMake testing only for "CXX" when deciding whether to apply the inline visibility flag.
Tested under 3.16.2.
Edited by Nick Hutchinson