Turn on some basic tsan annotations.

The most useful bit here is that tsan now knows the names of our threads.

Change-Id: I8eef8f31e954ffc373555b392d6d9678d76ead34
diff --git a/build/Android.common.mk b/build/Android.common.mk
index 26d4d22..a4cdc34 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -59,6 +59,7 @@
 endif
 
 art_debug_cflags := \
+	-DDYNAMIC_ANNOTATIONS_ENABLED=1 \
 	-UNDEBUG
 
 ART_HOST_CFLAGS := $(art_cflags) -DANDROID_SMP=1