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/compiler/utils/arm64/constants_arm64.h b/compiler/utils/arm64/constants_arm64.h
index c05c2f1..ecf9fbe 100644
--- a/compiler/utils/arm64/constants_arm64.h
+++ b/compiler/utils/arm64/constants_arm64.h
@@ -29,7 +29,7 @@
 namespace art {
 namespace arm64 {
 
-  constexpr unsigned int kCalleeSavedRegsSize = 20;
+constexpr unsigned int kCalleeSavedRegsSize = 20;
 
 }  // arm64
 }  // art