Fix bug where the closure-invocation method was not mangled correctly.

tests/language/language-leg.status

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 prefix language
 
 [ $component == leg && $checked ]
 *: Skip
 
 
@@ skipping 152 matching lines @@
 Private3Test: Fail # Expect.equals(expected: <-1>, actual: <The Ring>) fails.
 PrivateTest: Fail # Expect.equals(expected: <99>, actual: <499>) fails.
 PropertyFieldOverrideTest: Fail # Expect.equals(expected: <3>, actual: <null>) fails.
 ToStringAsFixedTest: Fail # Expect.equals(expected: <0.0000006>, actual: <0.0000010>) fails.
 TypedMessageTest: Fail # SyntaxError: Unexpected token this
 
 
 # Mapping of JS errors to Dart exceptions.
 Factory3Test: Fail # TypeError: Cannot call method 'prepend$1' of undefined
 MethodInvocationTest: Fail # TypeError: Cannot call method 'foo$0' of undefined
-NamedParametersPassingFalsyTest: Fail # TypeError: Object Instance of 'BoundClosure' has no method '$call$13'
 NullToStringTest: Fail # TypeError: Cannot call method 'get$toString' of undefined
 StackOverflowTest: Fail # RangeError: Maximum call stack size exceeded
 StackTraceTest: Fail # ReferenceError: stacktrace is not defined
 StringTest: Fail # TypeError: Object Hello has no method 'operator$indexSet$2'
 
 
 # Bad code.
 InstanceofTest: Fail # SyntaxError: Unexpected identifier
 
 
@@ skipping 141 matching lines @@
 # TODO(ahe): Categorize these failures.
 ClosureBreak1Test: Fail
 ClosureBreak2Test: Fail
 ClosureBreakTest: Fail
 ExecuteFinally3Test: Fail
 ExecuteFinally9Test: Fail
 
 
 [ $component == leg && $mode == release ]
 AssignTopMethodNegativeTest: Crash