vanir_config.mk:  Add clang/GCC specific flag options

Change-Id: I4d37140c3b393ef3fc9b2235bea51daf3b3d1105
Merge branch 'EXODUS' of https://github.com/VanirAOSP/build into HEAD

Conflicts:
	core/clang/config.mk
	core/combo/TARGET_linux-arm.mk