Allow mixing of thread offsets between 32 and 64bit architectures.

Begin a more full implementation x86-64 REX prefixes.
Doesn't implement 64bit thread offset support for the JNI compiler.

Change-Id: If9af2f08a1833c21ddb4b4077f9b03add1a05147
diff --git a/runtime/Android.mk b/runtime/Android.mk
index 1576905..e8224cd 100644
--- a/runtime/Android.mk
+++ b/runtime/Android.mk
@@ -294,6 +294,7 @@
 
 
 LIBART_ENUM_OPERATOR_OUT_HEADER_FILES := \
+	arch/x86_64/registers_x86_64.h \
 	base/mutex.h \
 	dex_file.h \
 	dex_instruction.h \