Revert "GeneratorFunction() makes generator instances"

test/mjsunit/harmony/generators-runtime.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 92 matching lines @@
   assertTrue(g instanceof GeneratorFunction);
 
   assertSame(Function, Object.getPrototypeOf(GeneratorFunction));
   assertTrue(g instanceof Function);
 
   assertEquals("function* g() { yield 1; }", g.toString());
 
   // Not all functions are generators.
   assertTrue(f instanceof Function);  // Sanity check.
   assertTrue(!(f instanceof GeneratorFunction));
-
-  assertTrue((new GeneratorFunction()) instanceof GeneratorFunction);
-  assertTrue(GeneratorFunction() instanceof GeneratorFunction);
 }
 TestGeneratorFunction();
 
 
 function TestPerGeneratorPrototype() {
   assertTrue((function*(){}).prototype !== (function*(){}).prototype);
   assertTrue((function*(){}).prototype !== g.prototype);
   assertTrue(g.prototype instanceof GeneratorFunctionPrototype);
   assertSame(GeneratorObjectPrototype, Object.getPrototypeOf(g.prototype));
   assertTrue(!(g.prototype instanceof Function));
   assertSame(typeof (g.prototype), "object");
 
   assertArrayEquals([], Object.getOwnPropertyNames(g.prototype));
 }
 TestPerGeneratorPrototype();