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/arch/arm/fault_handler_arm.cc b/runtime/arch/arm/fault_handler_arm.cc
index abce838..65a4952 100644
--- a/runtime/arch/arm/fault_handler_arm.cc
+++ b/runtime/arch/arm/fault_handler_arm.cc
@@ -109,7 +109,7 @@
 bool SuspensionHandler::Action(int sig, siginfo_t* info, void* context) {
   // These are the instructions to check for.  The first one is the ldr r0,[r9,#xxx]
   // where xxx is the offset of the suspend trigger.
-  uint32_t checkinst1 = 0xf8d90000 + Thread::ThreadSuspendTriggerOffset().Int32Value();
+  uint32_t checkinst1 = 0xf8d90000 + Thread::ThreadSuspendTriggerOffset<4>().Int32Value();
   uint16_t checkinst2 = 0x6800;
 
   struct ucontext *uc = (struct ucontext *)context;