Clean up Isolate usages in ast visitor and hydrogen.

src/ast.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 682 matching lines @@
     ASSERT(compare_type_ == NONE);
   }
 }
 
 
 // ----------------------------------------------------------------------------
 // Implementation of AstVisitor
 
 bool AstVisitor::CheckStackOverflow() {
   if (stack_overflow_) return true;
-  StackLimitCheck check(Isolate::Current());
+  StackLimitCheck check(isolate_);
   if (!check.HasOverflowed()) return false;
   return (stack_overflow_ = true);
 }
 
 
 void AstVisitor::VisitDeclarations(ZoneList<Declaration*>* declarations) {
   for (int i = 0; i < declarations->length(); i++) {
     Visit(declarations->at(i));
   }
 }
@@ skipping 355 matching lines @@
                        ZoneList<Statement*>* statements,
                        int pos)
     : label_(label),
       statements_(statements),
       position_(pos),
       compare_type_(NONE),
       entry_id_(AstNode::GetNextId()) {
 }
 
 } }  // namespace v8::internal