Make FastNewFunctionContextStub take slots parameter

src/compiler/js-generic-lowering.cc

Index: src/compiler/js-generic-lowering.cc
diff --git a/src/compiler/js-generic-lowering.cc b/src/compiler/js-generic-lowering.cc
index e07daf0c721936cd951d196b1af7b75eecf47611..0f9defd4ce5be39ff2f21a8f5cbec1a53dfda466 100644
--- a/src/compiler/js-generic-lowering.cc
+++ b/src/compiler/js-generic-lowering.cc
@@ -446,14 +446,9 @@ void JSGenericLowering::LowerJSCreateFunctionContext(Node* node) {
   int const slot_count = OpParameter<int>(node->op());
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
 
-  // Use the FastNewFunctionContextStub only for function contexts up maximum
-  // size.
-  if (slot_count <= FastNewFunctionContextStub::kMaximumSlots) {
-    Callable callable = CodeFactory::FastNewContext(isolate(), slot_count);
-    ReplaceWithStubCall(node, callable, flags);
-  } else {
-    ReplaceWithRuntimeCall(node, Runtime::kNewFunctionContext);
-  }
+  Callable callable = CodeFactory::FastNewFunctionContext(isolate());
+  node->InsertInput(zone(), 1, jsgraph()->Int32Constant(slot_count));
+  ReplaceWithStubCall(node, callable, flags);
 }