unix: delete asm.s
unix: delete asm.s

This contains a stub for func "use", which was deleted.

See issue https://golang.org/issue/16607

Change-Id: I7165ca55ad956ac449e950f2be6f53cfeb8e6ffa
Reviewed-on: https://go-review.googlesource.com/36720
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

multiplay/golang-sys,golang/sys,golang/sys,multiplay/golang-sys,golang/sys,multiplay/golang-sys,multiplay/golang-sys