runtime/cgo: since use register windows, crosscall1 doesn't have to save anything
runtime/cgo: since use register windows, crosscall1 doesn't have to save anything

...I hope.

Change-Id: I1313eb12cfaf667511a3e8115b2e4b0989a482b1

4ad/go,4ad/go,4ad/go,4ad/go,4ad/go,4ad/go,4ad/go,4ad/go