libgo: update to Go 1.11.1 release

Change-Id: Idbc3e39c195430bcc4f95ee112526e215f5c8cab
Reviewed-on: https://go-review.googlesource.com/c/140277
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
27 files changed