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

src/regexp/jsregexp.h

Index: src/regexp/jsregexp.h
diff --git a/src/regexp/jsregexp.h b/src/regexp/jsregexp.h
index d6a74ea19d77159ff8e4c4332330273e37c89748..3ce9f131110fd80bb904f38b02150dbf65ec7384 100644
--- a/src/regexp/jsregexp.h
+++ b/src/regexp/jsregexp.h
@@ -29,13 +29,6 @@ class RegExpImpl {
 #endif
   }
 
-  // Creates a regular expression literal in the old space.
-  // This function calls the garbage collector if necessary.
-  MUST_USE_RESULT static MaybeHandle<Object> CreateRegExpLiteral(
-      Handle<JSFunction> constructor,
-      Handle<String> pattern,
-      Handle<String> flags);
-
   // Returns a string representation of a regular expression.
   // Implements RegExp.prototype.toString, see ECMA-262 section 15.10.6.4.
   // This function calls the garbage collector if necessary.