Fix mock library to use new noSuchMethod signature.

pkg/pkg.status

Index: pkg/pkg.status
===================================================================
--- pkg/pkg.status	(revision 14483)
+++ pkg/pkg.status	(working copy)
@@ -9,12 +9,6 @@
 # arithmetic natively, i.e., the VM.
 fixnum/test/int_64_vm_test: Skip
 
-# Skip mock tests for now until the noSuchMethod code is fixed.
-
-unittest/test/mock_test: Skip
-unittest/test/mock_regexp_negative_test: Skip
-unittest/test/mock_stepwise_negative_test: Skip
-
 [$compiler == dart2dart]
 *: Skip
 
@@ -32,7 +26,6 @@
 [ $runtime == vm ]
 intl/test/find_default_locale_browser_test: Skip
 intl/test/date_time_format_http_request_test: Skip
-unittest/test/mock_test: Fail  # noSuchMethod InvocationMirror not correct yet.
 
 # Skip http request tests on Dartium while resolving an odd
 # error there that causes the tests to timeout.