[Turbofan] JSStackCheck operation missing an effect

A machine load is an effectful operation, but we didn't include
it in the effect chain.

Bug: v8:6929
Change-Id: I08a09c71dafd9dd7e5e40440a24751f2c5bcfae9
Reviewed-on: https://chromium-review.googlesource.com/718456
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48548}

src/compiler/js-generic-lowering.cc

@@ -745,7 +745,7 @@ void JSGenericLowering::LowerJSStackCheck(Node* node) {
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
 
-  Node* limit = graph()->NewNode(
+  Node* limit = effect = graph()->NewNode(
       machine()->Load(MachineType::Pointer()),
       jsgraph()->ExternalConstant(
           ExternalReference::address_of_stack_limit(isolate())),
@@ -761,6 +761,7 @@ void JSGenericLowering::LowerJSStackCheck(Node* node) {
 
   Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
   NodeProperties::ReplaceControlInput(node, if_false);
+  NodeProperties::ReplaceEffectInput(node, effect);
   Node* efalse = if_false = node;
 
   Node* merge = graph()->NewNode(common()->Merge(2), if_true, if_false);