[turbofan] Optimize string "length" property access based on types.

src/compiler/js-typed-lowering.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_TYPED_LOWERING_H_
 #define V8_COMPILER_JS_TYPED_LOWERING_H_
 
 #include "src/compiler/graph-reducer.h"
 #include "src/compiler/opcodes.h"
 #include "src/compiler/simplified-operator.h"
@@ skipping 24 matching lines @@
 
  private:
   friend class JSBinopReduction;
 
   Reduction ReduceJSAdd(Node* node);
   Reduction ReduceJSModulus(Node* node);
   Reduction ReduceJSBitwiseOr(Node* node);
   Reduction ReduceJSMultiply(Node* node);
   Reduction ReduceJSComparison(Node* node);
   Reduction ReduceJSLoadGlobal(Node* node);
+  Reduction ReduceJSLoadNamed(Node* node);
   Reduction ReduceJSLoadProperty(Node* node);
   Reduction ReduceJSStoreProperty(Node* node);
   Reduction ReduceJSLoadContext(Node* node);
   Reduction ReduceJSStoreContext(Node* node);
   Reduction ReduceJSLoadDynamicGlobal(Node* node);
   Reduction ReduceJSLoadDynamicContext(Node* node);
   Reduction ReduceJSEqual(Node* node, bool invert);
   Reduction ReduceJSStrictEqual(Node* node, bool invert);
   Reduction ReduceJSUnaryNot(Node* node);
   Reduction ReduceJSToBoolean(Node* node);
@@ skipping 33 matching lines @@
   JSGraph* jsgraph_;
   SimplifiedOperatorBuilder simplified_;
   Type* shifted_int32_ranges_[4];
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_JS_TYPED_LOWERING_H_