Do not use clang for mips target.

Clang assembler cannot compile some inlined assembly code
in valgrind_malloc_space-inl.h:192:5: error: used $at without ".set noat"
However, clang generated assembly code for runtime/mirror/array.cc
cannot be compiled by gas.

BUG: 18789639
BUG: 18807290
Change-Id: Ifdeb3c50f11cefc7f0d62c1d36fdd1f8b9344fb4
2 files changed