Remove the dependency of Zone on Isolate

src/regexp-macro-assembler.h

Index: src/regexp-macro-assembler.h
diff --git a/src/regexp-macro-assembler.h b/src/regexp-macro-assembler.h
index c2f8f4297fda571dcbc9ecbd6c7699ce00973936..60b83a4347f1cc28694b72eef541033d44d4c3c5 100644
--- a/src/regexp-macro-assembler.h
+++ b/src/regexp-macro-assembler.h
@@ -43,7 +43,7 @@ class RegExpMacroAssembler {
     kCheckStackLimit = true
   };
 
-  explicit RegExpMacroAssembler(Zone* zone);
+  RegExpMacroAssembler(Isolate* isolate, Zone* zone);
   virtual ~RegExpMacroAssembler();
   // The maximal number of pushes between stack checks. Users must supply
   // kCheckStackLimit flag to push operations (instead of kNoStackLimitCheck)
@@ -158,11 +158,13 @@ class RegExpMacroAssembler {
     return global_mode_ == GLOBAL;
   }
 
+  Isolate* isolate() const { return isolate_; }
   Zone* zone() const { return zone_; }
 
  private:
   bool slow_safe_compiler_;
   bool global_mode_;
+  Isolate* isolate_;
   Zone* zone_;
 };
 
@@ -185,7 +187,7 @@ class NativeRegExpMacroAssembler: public RegExpMacroAssembler {
   //        capture positions.
   enum Result { RETRY = -2, EXCEPTION = -1, FAILURE = 0, SUCCESS = 1 };
 
-  explicit NativeRegExpMacroAssembler(Zone* zone);
+  NativeRegExpMacroAssembler(Isolate* isolate, Zone* zone);
   virtual ~NativeRegExpMacroAssembler();
   virtual bool CanReadUnaligned();