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/x86/utility_x86.cc b/compiler/dex/quick/x86/utility_x86.cc
index bb5d387..e9faa7f 100644
--- a/compiler/dex/quick/x86/utility_x86.cc
+++ b/compiler/dex/quick/x86/utility_x86.cc
@@ -468,7 +468,7 @@
   return OpRegImm(op, r_dest, value);
 }
 
-LIR* X86Mir2Lir::OpThreadMem(OpKind op, ThreadOffset thread_offset) {
+LIR* X86Mir2Lir::OpThreadMem(OpKind op, ThreadOffset<4> thread_offset) {
   X86OpCode opcode = kX86Bkpt;
   switch (op) {
     case kOpBlx: opcode = kX86CallT;  break;