[turbofan] Hook up construct call counts.

Utilize the previously introduced construct call counts in the
JSInliningHeuristic to also handle constructor calls properly.

R=mvstanton@chromium.org

Review-Url: https://codereview.chromium.org/2026513003
Cr-Commit-Position: refs/heads/master@{#36585}

src/compiler/js-inlining-heuristic.cc

@@ -75,13 +75,24 @@ Reduction JSInliningHeuristic::Reduce(Node* node) {
 
   // Gather feedback on how often this call site has been hit before.
   int calls = -1;  // Same default as CallICNexus::ExtractCallCount.
-  // TODO(turbofan): We also want call counts for constructor calls.
   if (node->opcode() == IrOpcode::kJSCallFunction) {
     CallFunctionParameters p = CallFunctionParametersOf(node->op());
     if (p.feedback().IsValid()) {
       CallICNexus nexus(p.feedback().vector(), p.feedback().slot());
       calls = nexus.ExtractCallCount();
     }
+  } else {
+    DCHECK_EQ(IrOpcode::kJSCallConstruct, node->opcode());
+    CallConstructParameters p = CallConstructParametersOf(node->op());
+    if (p.feedback().IsValid()) {
+      int const extra_index =
+          p.feedback().vector()->GetIndex(p.feedback().slot()) + 1;
+      Handle<Object> feedback_extra(p.feedback().vector()->get(extra_index),
+                                    function->GetIsolate());
+      if (feedback_extra->IsSmi()) {
+        calls = Handle<Smi>::cast(feedback_extra)->value();
+      }
+    }
   }
 
   // ---------------------------------------------------------------------------