Set compiler flags

Detailed Description

Macros
#define	SETCOMP_OVERRIDE   0x0001
	may override old compiler info
#define	SETCOMP_ONLY_ID   0x0002
	cc has only 'id' field; the rest will be set to defaults corresponding to the program bitness
#define	SETCOMP_ONLY_ABI   0x0004
	ignore cc field complete, use only abiname
#define	SETCOMP_BY_USER   0x0008
	invoked by user, cannot be replaced by module/loader