go.crypt/ssh/terminal: declare TCGETS, TCSETS constants locally.
go.crypt/ssh/terminal: declare TCGETS, TCSETS constants locally.

Currently the ssh/terminal package cannot be compiled under gccgo. Even though gccgo may be running on linux, its syscall package is slightly different and does not contain these constants.

This proposal resolves the issue by declaring the two constants locally, as we've done for the *BSDs.

LGTM=hanwen, iant
R=hanwen, iant, gobot
CC=golang-codereviews
https://codereview.appspot.com/101670043

drhax9908/go.crypto,drhax9908/go.crypto,xman1101/terminal,xman1101/terminal