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/dex/quick/mips/int_mips.cc b/compiler/dex/quick/mips/int_mips.cc
index dfe8b35..2424dc5 100644
--- a/compiler/dex/quick/mips/int_mips.cc
+++ b/compiler/dex/quick/mips/int_mips.cc
@@ -270,7 +270,7 @@
   LOG(FATAL) << "Unexpected use of OpLea for Arm";
 }
 
-void MipsMir2Lir::OpTlsCmp(ThreadOffset offset, int val) {
+void MipsMir2Lir::OpTlsCmp(ThreadOffset<4> offset, int val) {
   LOG(FATAL) << "Unexpected use of OpTlsCmp for Arm";
 }