Clang: Silence warnings (2/3)

With GCC >=4.7 Clang generates a lot of noise with various compiler flags,
and can even break the builds when using Flags like Graphite.  This can be
reproduced by doing the following:

Setting TARGET_EXTRA_CFLAGS with Graphite flags such as these
TARGET_EXTRA_CFLAGS +=	-fgraphite-identity \
			-floop-block \
			-floop-strip-mine \
			-ftree-loop-distribution \
			-ftree-loop-linear

Causes the following errors to occure and the builds to fail:

clang: error: argument unused during compilation: '-fgraphite-identity'
                                                  '-floop-block'
                                                  '-floop-strip-mine'
                                                  '-ftree-loop-distribution'
                                                  '-ftree-loop-linear'

Silence the errors by passing the -Qunused-arguments for CFLAGS

Singed-off-by: Paul Beeler <sparksco@gmail.com>

Conflicts:
	v8/renderscript/rs_support/Android.mk

Change-Id: Ic334f3120a727f54e22fe9bd18f176d69b06a84d
fix clang error:
build is failing with warning for strict-aliasing flag -Wstrict-aliasing=3
Signed-off-by: Paul Beeler <sparksco@gmail.com>

Conflicts:
	v8/renderscript/rs_support/Android.mk

Change-Id: I26cd808efb2f10620316d9bf35c3d9a3e7d184b1