Thumb2 Backend: Update Code objects with mode, separate Assembler methods for Thumb2

src/assembler.cc

Index: src/assembler.cc
diff --git a/src/assembler.cc b/src/assembler.cc
index fbff62dd65ef87773461b377ea09f557068c0dc7..cecc80617330f3bc4918f6de99fb1b776a0d964b 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -679,7 +679,7 @@ void RelocIterator::next() {
 
 RelocIterator::RelocIterator(Code* code, int mode_mask) {
   rinfo_.host_ = code;
-  rinfo_.pc_ = code->instruction_start();
+  rinfo_.pc_ = code->entry();
   rinfo_.data_ = 0;
   // Relocation info is read backwards.
   pos_ = code->relocation_start() + code->relocation_size();