[Cmake] Determining host compiler/OS from CMake

[John Biddiscombe]

> So you could do:
> SOURCE_FILES_FLAGS("-flag -flag2" file1 file2 CMAKE_COMPILER_IS_GNUCXX)

Whilst you chaps are organizing the extensions, I'd love to see

SOURCE_FILES_LINKER FLAGS_LITERAL("-any /string +allowed \here" file1 file2
CMAKE_COMPILER_IS_GNUCXX)

SOURCE_FILES_COMPILER FLAGS_LITERAL("-flag -flag2" file1 file2
CMAKE_COMPILER_IS_GNUCXX)

The specific aim being to allow any linker command line options - or any
compiler command line options to be added. The keyword LITERAL stating this
explicitly and leaving it to the user to ensure it is valid for the
platform/compiler

(Is this compatible with what you had in mind?)

Thanks

JB