[turbofan] Assign proper types to Parameter nodes.

src/compiler/typer.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_TYPER_H_
 #define V8_COMPILER_TYPER_H_
 
 #include "src/compiler/graph.h"
 #include "src/compiler/operation-typer.h"
 #include "src/globals.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Forward declarations.
 class LoopVariableOptimizer;
 
 class V8_EXPORT_PRIVATE Typer {
  public:
-  Typer(Isolate* isolate, Graph* graph);
+  enum Flag : uint8_t {
+    kNoFlags = 0,
+    kThisIsReceiver = 1u << 0,       // Parameter this is an Object.
+    kNewTargetIsReceiver = 1u << 1,  // Parameter new.target is an Object.
+  };
+  typedef base::Flags<Flag> Flags;
+
+  Typer(Isolate* isolate, Flags flags, Graph* graph);
   ~Typer();
 
   void Run();
   // TODO(bmeurer,jarin): Remove this once we have a notion of "roots" on Graph.
   void Run(const ZoneVector<Node*>& roots,
            LoopVariableOptimizer* induction_vars);
 
  private:
   class Visitor;
   class Decorator;
 
+  Flags flags() const { return flags_; }
   Graph* graph() const { return graph_; }
   Zone* zone() const { return graph()->zone(); }
   Isolate* isolate() const { return isolate_; }
   OperationTyper* operation_typer() { return &operation_typer_; }
 
   Isolate* const isolate_;
+  Flags const flags_;
   Graph* const graph_;
   Decorator* decorator_;
   TypeCache const& cache_;
   OperationTyper operation_typer_;
 
   Type* singleton_false_;
   Type* singleton_true_;
   Type* singleton_the_hole_;
   Type* falsish_;
   Type* truish_;
 
   DISALLOW_COPY_AND_ASSIGN(Typer);
 };
 
+DEFINE_OPERATORS_FOR_FLAGS(Typer::Flags);
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_TYPER_H_