Fix TARGET_GLOBAL_CLANG_FLAGS not filtering TARGET_GLOBAL_CPPFLAGS,
& add -fforce-mem -fforce-addr & -fspeculative-prefetching to
CLANG_CONFIG_UNKNOWN_CFLAGS

Change-Id: I38ae521882537df4cc4627fe1ca7145e7dc9a31b
Actually use prebuilt clang

Change-Id: I2193624947974ca47558745f10177d59329bbb88
MY GOTO & LDFLAGS

Change-Id: I3ed147f180267db975ee556a4730c2c1dad2d554