[compiler] Delete extra map check in StringIterator.

src/compiler/js-builtin-reducer.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_JS_BUILTIN_REDUCER_H_
 #define V8_COMPILER_JS_BUILTIN_REDUCER_H_
 
 #include "src/base/compiler-specific.h"
 #include "src/base/flags.h"
 #include "src/compiler/graph-reducer.h"
@@ skipping 20 matching lines @@
     : public NON_EXPORTED_BASE(AdvancedReducer) {
  public:
   // Flags that control the mode of operation.
   enum Flag {
     kNoFlags = 0u,
     kDeoptimizationEnabled = 1u << 0,
   };
   typedef base::Flags<Flag> Flags;
 
   JSBuiltinReducer(Editor* editor, JSGraph* jsgraph, Flags flags,
-                   CompilationDependencies* dependencies);
+                   CompilationDependencies* dependencies,
+                   Handle<Context> native_context);
   ~JSBuiltinReducer() final {}
 
   Reduction Reduce(Node* node) final;
 
  private:
   Reduction ReduceArrayPop(Node* node);
   Reduction ReduceArrayPush(Node* node);
   Reduction ReduceDateGetTime(Node* node);
   Reduction ReduceGlobalIsFinite(Node* node);
   Reduction ReduceGlobalIsNaN(Node* node);
@@ skipping 45 matching lines @@
                                           FieldAccess const& access);
 
   Node* ToNumber(Node* value);
   Node* ToUint32(Node* value);
 
   Flags flags() const { return flags_; }
   Graph* graph() const;
   Factory* factory() const;
   JSGraph* jsgraph() const { return jsgraph_; }
   Isolate* isolate() const;
+  Handle<Context> native_context() const { return native_context_; }
   CommonOperatorBuilder* common() const;
   SimplifiedOperatorBuilder* simplified() const;
   JSOperatorBuilder* javascript() const;
   CompilationDependencies* dependencies() const { return dependencies_; }
 
   CompilationDependencies* const dependencies_;
   Flags const flags_;
   JSGraph* const jsgraph_;
+  Handle<Context> const native_context_;
   TypeCache const& type_cache_;
 };
 
 DEFINE_OPERATORS_FOR_FLAGS(JSBuiltinReducer::Flags)
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_JS_BUILTIN_REDUCER_H_