Support 32-bit volatiles.

Change-Id: If40ead8e13986d589ac1d1637034e25fc4108189
diff --git a/build/Android.common.mk b/build/Android.common.mk
index b4fb7aa..7a31ceb 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -24,7 +24,7 @@
 	art/src \
 	dalvik/libdex
 
-ART_CFLAGS := \
+art_cflags := \
 	-O2 \
 	-ggdb3 \
 	-Wall \
@@ -35,6 +35,16 @@
 	-fno-align-jumps \
 	-fstrict-aliasing
 
+ART_HOST_CFLAGS := $(art_cflags) -DANDROID_SMP=1
+
+ART_TARGET_CFLAGS := $(art_cflags)
+ifeq ($(TARGET_CPU_SMP),true)
+  ART_TARGET_CFLAGS += -DANDROID_SMP=1
+else
+  ART_TARGET_CFLAGS += -DANDROID_SMP=0
+endif
+
+
 DEX2OAT_SRC_FILES := \
 	src/dex2oat.cc