Use a class field instead of global FLAG_debug_code in assember and

src/arm/assembler-arm.h

Index: src/arm/assembler-arm.h
diff --git a/src/arm/assembler-arm.h b/src/arm/assembler-arm.h
index cf94e831443a29ddf1cb45a0b20e227110ab0946..22eee0f95ea89c256e52acc9aff1d2ba70ea5192 100644
--- a/src/arm/assembler-arm.h
+++ b/src/arm/assembler-arm.h
@@ -554,6 +554,9 @@ class Assembler : public Malloced {
   Assembler(void* buffer, int buffer_size);
   ~Assembler();
 
+  // Overrides the default provided by FLAG_debug_code.
+  void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
+
   // GetCode emits any pending (non-emitted) code and fills the descriptor
   // desc. GetCode() is idempotent; it returns the same result if no other
   // Assembler functions are invoked in between GetCode() calls.
@@ -1154,6 +1157,8 @@ class Assembler : public Malloced {
   void CheckConstPool(bool force_emit, bool require_jump);
 
  protected:
+  bool emit_debug_code() const { return emit_debug_code_; }
+
   int buffer_space() const { return reloc_info_writer.pos() - pc_; }
 
   // Read/patch instructions
@@ -1282,6 +1287,7 @@ class Assembler : public Malloced {
 
   PositionsRecorder positions_recorder_;
   bool allow_peephole_optimization_;
+  bool emit_debug_code_;
   friend class PositionsRecorder;
   friend class EnsureSpace;
 };