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/mips/thread_mips.cc b/runtime/arch/mips/thread_mips.cc
index f5d211f..a451496 100644
--- a/runtime/arch/mips/thread_mips.cc
+++ b/runtime/arch/mips/thread_mips.cc
@@ -22,9 +22,9 @@
 namespace art {
 
 void Thread::InitCpu() {
-  CHECK_EQ(THREAD_FLAGS_OFFSET, OFFSETOF_MEMBER(Thread, state_and_flags_));
-  CHECK_EQ(THREAD_CARD_TABLE_OFFSET, OFFSETOF_MEMBER(Thread, card_table_));
-  CHECK_EQ(THREAD_EXCEPTION_OFFSET, OFFSETOF_MEMBER(Thread, exception_));
+  CHECK_EQ(THREAD_FLAGS_OFFSET, ThreadFlagsOffset<4>().Int32Value());
+  CHECK_EQ(THREAD_CARD_TABLE_OFFSET, CardTableOffset<4>().Int32Value());
+  CHECK_EQ(THREAD_EXCEPTION_OFFSET, ExceptionOffset<4>().Int32Value());
 }
 
 void Thread::CleanupCpu() {