libgo: support for sparc64 GNU/Linux

Fix lfstack code to work with sparc64 GNU/Linux address map.

Force alignment of epollevent.  To make this work reliably, pass
GOARCH explicitly to mkrsysinfo.sh.

Patch by Vladimir Mezentsev.

Change-Id: I01a61a72617e9340821f75ffa5446d5ae3532a36
Reviewed-on: https://go-review.googlesource.com/44494
Reviewed-by: Ian Lance Taylor <iant@golang.org>
4 files changed