[turbofan] Add support to lower Function.prototype.call.

src/compiler/js-builtin-reducer.h

Index: src/compiler/js-builtin-reducer.h
diff --git a/src/compiler/js-builtin-reducer.h b/src/compiler/js-builtin-reducer.h
index e3620dc22fbf2f4c41aa0f042b3f33764350a195..772cbdbf25e141b024c8afe0775d315b85346edd 100644
--- a/src/compiler/js-builtin-reducer.h
+++ b/src/compiler/js-builtin-reducer.h
@@ -14,6 +14,7 @@ namespace compiler {
 // Forward declarations.
 class CommonOperatorBuilder;
 class JSGraph;
+class JSOperatorBuilder;
 class MachineOperatorBuilder;
 class SimplifiedOperatorBuilder;
 
@@ -26,15 +27,18 @@ class JSBuiltinReducer final : public AdvancedReducer {
   Reduction Reduce(Node* node) final;
 
  private:
+  Reduction ReduceFunctionCall(Node* node);
   Reduction ReduceMathMax(Node* node);
   Reduction ReduceMathImul(Node* node);
   Reduction ReduceMathFround(Node* node);
 
-  JSGraph* jsgraph() const { return jsgraph_; }
   Graph* graph() const;
+  JSGraph* jsgraph() const { return jsgraph_; }
+  Isolate* isolate() const;
   CommonOperatorBuilder* common() const;
   MachineOperatorBuilder* machine() const;
   SimplifiedOperatorBuilder* simplified() const;
+  JSOperatorBuilder* javascript() const;
 
   JSGraph* jsgraph_;
 };