code review 139040043: runtime: fix windows build

runtime: fix windows build

#ifdef'ed out code wasn't updated for argp change.

[rsc, 2014-09-01 21:36:40]

Hello iant (cc: golang-codereviews@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2014-09-01 21:36:47]

*** Submitted as https://code.google.com/p/go/source/detail?r=5859e2509c96 ***

runtime: fix windows build

#ifdef'ed out code wasn't updated for argp change.

TBR=iant
CC=golang-codereviews
https://codereview.appspot.com/139040043

[iant, 2014-09-02 13:58:13]

LGTM