[js] Avoid %_ClassOf for collection builtins.

src/compiler/js-intrinsic-lowering.cc

Index: src/compiler/js-intrinsic-lowering.cc
diff --git a/src/compiler/js-intrinsic-lowering.cc b/src/compiler/js-intrinsic-lowering.cc
index 28c6b940b020954eefd19cc5df2bc68d925edc99..6f916bed6d7f064c0029ea45759f8b86d4d16112 100644
--- a/src/compiler/js-intrinsic-lowering.cc
+++ b/src/compiler/js-intrinsic-lowering.cc
@@ -56,6 +56,18 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceIsInstanceType(node, JS_TYPED_ARRAY_TYPE);
     case Runtime::kInlineIsJSProxy:
       return ReduceIsInstanceType(node, JS_PROXY_TYPE);
+    case Runtime::kInlineIsJSMap:
+      return ReduceIsInstanceType(node, JS_MAP_TYPE);
+    case Runtime::kInlineIsJSSet:
+      return ReduceIsInstanceType(node, JS_SET_TYPE);
+    case Runtime::kInlineIsJSMapIterator:
+      return ReduceIsInstanceType(node, JS_MAP_ITERATOR_TYPE);
+    case Runtime::kInlineIsJSSetIterator:
+      return ReduceIsInstanceType(node, JS_SET_ITERATOR_TYPE);
+    case Runtime::kInlineIsJSWeakMap:
+      return ReduceIsInstanceType(node, JS_WEAK_MAP_TYPE);
+    case Runtime::kInlineIsJSWeakSet:
+      return ReduceIsInstanceType(node, JS_WEAK_SET_TYPE);

[rmcilroy, 2017/05/05 13:45:31]

Does it make sense to add these as intrinsics to the interpreter as well? We
currently call out to the runtime for all these that you added here.

[Benedikt Meurer, 2017/05/05 14:00:58]

Ideally this code should be obsolete soon with a CSA based Maps/Sets. Maybe
until then, handling it in the interpreter might be beneficial indeed.

     case Runtime::kInlineIsJSReceiver:
       return ReduceIsJSReceiver(node);
     case Runtime::kInlineIsSmi: