Re-enable clang for Mips/Mips64 targets.

The build-time errors described in
  https://android-review.googlesource.com/#/c/120512
are no longer happening.

BUG: 18807290
BUG: 18789639

Change-Id: I195bbb7d102fecd6a6e6a3357b0863dd6fddb01f
diff --git a/build/Android.common_build.mk b/build/Android.common_build.mk
index 5beb959..d1724cc 100644
--- a/build/Android.common_build.mk
+++ b/build/Android.common_build.mk
@@ -83,19 +83,10 @@
 else
 ART_TARGET_CLANG := false
 endif
-
-ifeq ($(TARGET_ARCH)|$(ART_TARGET_CLANG),mips|true)
-  # b/18807290, Clang generated mips assembly code for array.cc
-  # cannot be compiled by gas.
-  # b/18789639, Clang assembler cannot compile inlined assembly code in
-  # valgrind_malloc_space-inl.h:192:5: error: used $at without ".set noat"
-  $(warning Clang is disabled for the mips target)
-endif
 ART_TARGET_CLANG_arm :=
 ART_TARGET_CLANG_arm64 :=
-# TODO: Enable clang mips when b/18807290 and b/18789639 are fixed.
-ART_TARGET_CLANG_mips := false
-ART_TARGET_CLANG_mips64 := false
+ART_TARGET_CLANG_mips :=
+ART_TARGET_CLANG_mips64 :=
 ART_TARGET_CLANG_x86 :=
 ART_TARGET_CLANG_x86_64 :=