[CMake] Objective-C support

[Emmanuel Blot]

Hi,

What is the recommended way to specify compiler flags for Objective-C
source files?

Objective-C is not defined as a specific language in the default CMake
modules (vs. C and C++ for exemple), so CMake does not seem to handle
OBJC flags at all.

How to define OBJCFLAGS for a whole project, in such a way that those
flags are only applied to .m source files, not the other source files
(.c, .cxx, etc.)?

Thanks,
Manu