[CMake] PROJECT() command when cross compiling

[Kishore]

It seems that the PROJECT() command does a fair bit behind the scenes and is 
not documented enough. It seems to "reset" several variable created before it 
was _first_ called.

Since i use cmake from cross compilation, i have created Platform files for 
Generic-gcc.cmake and Generic-gcc-uc3b1256.cmake (for the processor that I 
use)

1) It seems that these files are invoked inside the PROJECT() command
2) The platform files set up some needed variables such as CMAKE_C_FLAGS
3) When the PROJECT() command finishes, the variable CMAKE_C_FLAGS is again 
empty.

The above is only true on the first run of cmake and hence executing "make 
rebuild_cache" overcomes the issue. Bug?
-- 
Cheers!
Kishore