dart2js: set needsTearOff when creating the getter/setter stubs in the new emitter.

dart2js: set needsTearOff when creating the getter/setter stubs in the new emitter.

The Method constructor requires the booleans to be set:

  Method(this.element, this.name, this.code, {this.needsTearOff}) {
    assert(needsTearOff != null);

R=zarah@google.com

Committed: https://code.google.com/p/dart/source/detail?r=43037

[floitsch, 2015-01-21 13:49:50]

floitsch@google.com changed reviewers:
+ zarah@google.com

[zarah, 2015-01-21 13:52:55]

LGTM

[floitsch, 2015-01-21 14:01:19]

Committed patchset #1 (id:1) manually as 43037 (presubmit successful).