Output the flag being checked before checking the flag to make it easier to determine exactly which check failed. Change-Id: I692f5287f985acb4a3061dd54f7c5a8729def83b
- Move CXX flags stuff into build/cxx_flags.cmake. - include CMake modules where they're used. - Add ENABLE_WERROR flag-- enables warnings as errors. - Add -Wshorten-64-to-32 and -Wnarrowing to CXX flags. Change-Id: I5d93a39a3eff6ae81f9e094927b8f0cb9f36bbb0