Introduce a BuiltinsConstructStub that sets up new.target and does a [[call]] per ES6 9.3.2

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index e45baeb28504ce2cc230fe119b33e87ec9899d3f..5abf5c8f96897455b4e0a011c0db2b9ed7ed2fa1 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -288,6 +288,7 @@ namespace internal {
   V(ownKeys_string, "ownKeys")                                   \
   V(preventExtensions_string, "preventExtensions")               \
   V(private_api_string, "private_api")                           \
+  V(Promise_string, "Promise")                                   \
   V(proto_string, "__proto__")                                   \
   V(prototype_string, "prototype")                               \
   V(query_colon_string, "(?:)")                                  \