[turbofan] Assign proper types to Parameter nodes.

src/compiler/typer.h

Index: src/compiler/typer.h
diff --git a/src/compiler/typer.h b/src/compiler/typer.h
index 4b91d1d7c112a04fad2b592ed2542b988d76ee01..7f6f90a51753461355b8e7325ee9c55c534560c3 100644
--- a/src/compiler/typer.h
+++ b/src/compiler/typer.h
@@ -18,7 +18,14 @@ 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();
@@ -30,12 +37,14 @@ class V8_EXPORT_PRIVATE Typer {
   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_;
@@ -50,6 +59,8 @@ class V8_EXPORT_PRIVATE Typer {
   DISALLOW_COPY_AND_ASSIGN(Typer);
 };
 
+DEFINE_OPERATORS_FOR_FLAGS(Typer::Flags);
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8