[turbofan] Enforce native context specialization.

src/compiler/js-call-reducer.h

 // Copyright 2015 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_CALL_REDUCER_H_
 #define V8_COMPILER_JS_CALL_REDUCER_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/graph-reducer.h"
 
@@ skipping 13 matching lines @@
  public:
   // Flags that control the mode of operation.
   enum Flag {
     kNoFlags = 0u,
     kBailoutOnUninitialized = 1u << 0,
     kDeoptimizationEnabled = 1u << 1
   };
   typedef base::Flags<Flag> Flags;
 
   JSCallReducer(Editor* editor, JSGraph* jsgraph, Flags flags,
-                MaybeHandle<Context> native_context)
+                Handle<Context> native_context)
       : AdvancedReducer(editor),
         jsgraph_(jsgraph),
         flags_(flags),
         native_context_(native_context) {}
 
   Reduction Reduce(Node* node) final;
 
  private:
   Reduction ReduceArrayConstructor(Node* node);
   Reduction ReduceNumberConstructor(Node* node);
   Reduction ReduceFunctionPrototypeApply(Node* node);
   Reduction ReduceFunctionPrototypeCall(Node* node);
   Reduction ReduceJSCallConstruct(Node* node);
   Reduction ReduceJSCallFunction(Node* node);
 
-  MaybeHandle<Context> GetNativeContext(Node* node);
-
   Graph* graph() const;
   Flags flags() const { return flags_; }
   JSGraph* jsgraph() const { return jsgraph_; }
   Isolate* isolate() const;
-  MaybeHandle<Context> native_context() const { return native_context_; }
+  Handle<Context> native_context() const { return native_context_; }
   CommonOperatorBuilder* common() const;
   JSOperatorBuilder* javascript() const;
   SimplifiedOperatorBuilder* simplified() const;
 
   JSGraph* const jsgraph_;
   Flags const flags_;
-  MaybeHandle<Context> const native_context_;
+  Handle<Context> const native_context_;
 };
 
 DEFINE_OPERATORS_FOR_FLAGS(JSCallReducer::Flags)
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_JS_CALL_REDUCER_H_