Tell the linker to not treat its input as Objective C/C++ source.

Flags in CMAKE_CXX_FLAGS are passed to both compile and link commands.

A cleaner solution would be to use set_source_files_properties().
However, currently there are headers (StdThread.h, maybe more) that contain
Objective syntax. So it is not easy to determine exactly which source files
should be compiled as Objective C/C++ and that set can quickly change when
certain #include directives are modified. The solution for that would be to
move all uses of Objective syntax to implementation (.cpp) files and then
apply set_source_files_properties() to those.

CMakeLists.txt

@@ -102,6 +102,7 @@ endif()
 if (APPLE)
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -x objective-c++")
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -x objective-c")
+	set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -x none")
 	FIND_LIBRARY(ATB_LIBRARY AudioToolbox)
 	FIND_LIBRARY(AU_LIBRARY AudioUnit)		
 	FIND_LIBRARY(CARBON_LIBRARY Carbon)