[Cmake] Specifying my own file extension

[Mathieu Malaterre]

Hi all,

	I have some file where the extension is .S (assembly code) but still I 
compile them with gcc. Is there a way to specify this in a CMakeList.txt 
or should I hack

CMake/Source/cmSystemTools.cxx :

cmSystemTools::FileFormat cmSystemTools::GetFileFormat(const char* cext)
{
	...
}


Thanks
mathieu