Revert of [turbofan] Add initial support for global specialization.

src/compiler/js-global-specialization.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_GLOBAL_SPECIALIZATION_H_
-#define V8_COMPILER_JS_GLOBAL_SPECIALIZATION_H_
-
-#include "src/base/flags.h"
-#include "src/compiler/graph-reducer.h"
-#include "src/compiler/simplified-operator.h"
-
-namespace v8 {
-namespace internal {
-
-// Forward declarations.
-class CompilationDependencies;
-
-
-namespace compiler {
-
-// Forward declarations.
-class JSGraph;
-class JSOperatorBuilder;
-
-
-// Specializes a given JSGraph to a given GlobalObject, potentially constant
-// folding some {LoadGlobal} nodes or strength reducing some {StoreGlobal}
-// nodes.
-class JSGlobalSpecialization final : public AdvancedReducer {
- public:
-  // Flags that control the mode of operation.
-  enum Flag {
-    kNoFlags = 0u,
-    kDeoptimizationEnabled = 1u << 0,
-    kTypingEnabled = 1u << 1
-  };
-  typedef base::Flags<Flag> Flags;
-
-  JSGlobalSpecialization(Editor* editor, JSGraph* jsgraph, Flags flags,
-                         Handle<GlobalObject> global_object,
-                         CompilationDependencies* dependencies);
-
-  Reduction Reduce(Node* node) final;
-
- private:
-  Reduction ReduceJSLoadGlobal(Node* node);
-  Reduction ReduceJSStoreGlobal(Node* node);
-  Reduction ReduceLoadFromPropertyCell(Node* node,
-                                       Handle<PropertyCell> property_cell);
-  Reduction ReduceStoreToPropertyCell(Node* node,
-                                      Handle<PropertyCell> property_cell);
-
-  Reduction Replace(Node* node, Node* value, Node* effect = nullptr,
-                    Node* control = nullptr) {
-    ReplaceWithValue(node, value, effect, control);
-    return Changed(value);
-  }
-  Reduction Replace(Node* node, Handle<Object> value);
-
-  Graph* graph() const;
-  JSGraph* jsgraph() const { return jsgraph_; }
-  Isolate* isolate() const;
-  JSOperatorBuilder* javascript() const;
-  SimplifiedOperatorBuilder* simplified() { return &simplified_; }
-  Flags flags() const { return flags_; }
-  Handle<GlobalObject> global_object() const { return global_object_; }
-  CompilationDependencies* dependencies() const { return dependencies_; }
-
-  JSGraph* const jsgraph_;
-  Flags const flags_;
-  Handle<GlobalObject> global_object_;
-  CompilationDependencies* const dependencies_;
-  SimplifiedOperatorBuilder simplified_;
-
-  DISALLOW_COPY_AND_ASSIGN(JSGlobalSpecialization);
-};
-
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_COMPILER_JS_GLOBAL_SPECIALIZATION_H_