[turbofan] Remove unused function_type_ from Typer.

This is never passed to the Typer, and actually wouldn't work
anyways, since we cannot derive any meaningful types for
Parameters in JavaScript.

R=mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2171723002
Cr-Commit-Position: refs/heads/master@{#37944}

src/compiler/typer.cc

@@ -31,12 +31,11 @@ class Typer::Decorator final : public GraphDecorator {
 };
 
 Typer::Typer(Isolate* isolate, Graph* graph, Flags flags,
-             CompilationDependencies* dependencies, FunctionType* function_type)
+             CompilationDependencies* dependencies)
     : isolate_(isolate),
       graph_(graph),
       flags_(flags),
       dependencies_(dependencies),
-      function_type_(function_type),
       decorator_(nullptr),
       cache_(TypeCache::Get()),
       operation_typer_(isolate, zone()) {
@@ -625,17 +624,7 @@ Type* Typer::Visitor::TypeIfException(Node* node) { return Type::Any(); }
 
 // Common operators.
 
-
-Type* Typer::Visitor::TypeParameter(Node* node) {
-  if (FunctionType* function_type = typer_->function_type()) {
-    int const index = ParameterIndexOf(node->op());
-    if (index >= 0 && index < function_type->Arity()) {
-      return function_type->Parameter(index);
-    }
-  }
-  return Type::Any();
-}
-
+Type* Typer::Visitor::TypeParameter(Node* node) { return Type::Any(); }
 
 Type* Typer::Visitor::TypeOsrValue(Node* node) { return Type::Any(); }
 

src/compiler/typer.h

@@ -31,8 +31,7 @@ class Typer {
   typedef base::Flags<Flag> Flags;
 
   Typer(Isolate* isolate, Graph* graph, Flags flags = kNoFlags,
-        CompilationDependencies* dependencies = nullptr,
-        FunctionType* function_type = nullptr);
+        CompilationDependencies* dependencies = nullptr);
   ~Typer();
 
   void Run();
@@ -48,14 +47,12 @@ class Typer {
   Isolate* isolate() const { return isolate_; }
   Flags flags() const { return flags_; }
   CompilationDependencies* dependencies() const { return dependencies_; }
-  FunctionType* function_type() const { return function_type_; }
   OperationTyper* operation_typer() { return &operation_typer_; }
 
   Isolate* const isolate_;
   Graph* const graph_;
   Flags const flags_;
   CompilationDependencies* const dependencies_;
-  FunctionType* function_type_;
   Decorator* decorator_;
   TypeCache const& cache_;
   OperationTyper operation_typer_;