ARM64: Use libvixld when compiling for debug mode.

VIXL debug mode checks are valuable to catch dangerous code that can
lead to bugs.

This patch includes a couple of fixes for issues spotted by VIXL in debug mode.

Change-Id: I388ae1ffd9256ad74d0b6ce06f79cc7927a5f28a
diff --git a/build/Android.common_build.mk b/build/Android.common_build.mk
index bac0ff3..7395164 100644
--- a/build/Android.common_build.mk
+++ b/build/Android.common_build.mk
@@ -252,6 +252,7 @@
 art_debug_cflags := \
   $(ART_DEBUG_OPT_FLAG) \
   -DDYNAMIC_ANNOTATIONS_ENABLED=1 \
+  -DVIXL_DEBUG \
   -UNDEBUG
 
 # Assembler flags for non-debug ART and ART tools.