Implement operator== and hashCode for bound closures.

sdk/lib/_internal/compiler/implementation/closure.dart

Index: sdk/lib/_internal/compiler/implementation/closure.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/closure.dart	(revision 23339)
+++ sdk/lib/_internal/compiler/implementation/closure.dart	(working copy)
@@ -112,8 +112,11 @@
               // classes (since the emitter sorts classes by their id).
               compiler.getNextFreeClassId(),
               STATE_DONE) {
-    compiler.closureClass.ensureResolved(compiler);
-    supertype = compiler.closureClass.computeType(compiler);
+    ClassElement superclass = methodElement.isInstanceMember()
+        ? compiler.boundClosureClass
+        : compiler.closureClass;
+    superclass.ensureResolved(compiler);
+    supertype = superclass.computeType(compiler);
     interfaces = const Link<DartType>();
     allSupertypes = const Link<DartType>().prepend(supertype);
     thisType = rawType = new InterfaceType(this);