CMakeRCCompiler: Handle uppercase 'RC' as resource file format extension

We already match lowercase 'rc'.  Add 'RC' too.  The latter is listed in
other CMake<LANG>Compiler modules as ignored for their languages already.

Signed-off-by: Tim Blechmann <tim@klingt.org>
Process hex version numbers appropriately.
Merge topic 'windows-RC-extension' into next

514c2e3d CMakeRCCompiler: Handle uppercase 'RC' as resource file format extension
Merge topic 'WriteCompilerDetectionHeader-compiler-versions' into next

3cbc0190 Process hex version numbers appropriately.