This change updates the config to support multiple compilers by moving
CC_.* to CC_GCC_.* to make room for other compilers.
We also update gen_in_frags.sh to check for a default cc.
Signed-off-by: Ray Donnelly <mingw.android@gmail.com>
Reviewed-by: Yann Diorcet <diorcetyann@gmail.com>
Reviewed-by: Bryan Hundven <bryanhundven@gmail.com>