Revert "disable Krait for Mac builds to avoid assembler issues"

This doesn't seem to be a problem any more, and mac builds
that differ from linux builds is causing other problems.

This reverts commit 7c40fb95dc90ed092f435c769b4bbb494d453674.

Bug: 24339250
Change-Id: I8a0da11df42d58ba9c3ded4571f1db870f400a21
diff --git a/core/clang/arm.mk b/core/clang/arm.mk
index f76a182..ceb4a5a 100644
--- a/core/clang/arm.mk
+++ b/core/clang/arm.mk
@@ -10,11 +10,6 @@
   CLANG_CONFIG_arm_EXTRA_CFLAGS += -mcpu=krait
 endif
 
-ifeq ($(HOST_OS),darwin)
-  # Darwin is really bad at dealing with idiv/sdiv. Don't use krait on Darwin.
-  CLANG_CONFIG_arm_EXTRA_CFLAGS += -mcpu=cortex-a9
-endif
-
 CLANG_CONFIG_arm_EXTRA_CPPFLAGS :=
 
 CLANG_CONFIG_arm_EXTRA_LDFLAGS :=