Fix full code generator to not use --debug-code if it is in

src/x64/assembler-x64.h

Index: src/x64/assembler-x64.h
===================================================================
--- src/x64/assembler-x64.h	(revision 12237)
+++ src/x64/assembler-x64.h	(working copy)
@@ -561,6 +561,11 @@
   // Overrides the default provided by FLAG_debug_code.
   void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
 
+  // Avoids using instructions that vary in size in unpredictable ways between
+  // the snapshot and the running VM.  This is needed by the full compiler so
+  // that it can recompile code with debug support and fix the PC.
+  void set_predictable_code_size(bool value) { predictable_code_size_ = 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.
@@ -1433,6 +1438,7 @@
 
  protected:
   bool emit_debug_code() const { return emit_debug_code_; }
+  bool predictable_code_size() const { return predictable_code_size_; }
 
  private:
   byte* addr_at(int pos)  { return buffer_ + pos; }
@@ -1637,6 +1643,7 @@
   PositionsRecorder positions_recorder_;
 
   bool emit_debug_code_;
+  bool predictable_code_size_;
 
   friend class PositionsRecorder;
 };