runtime, net: fix build errors on AIX

Change-Id: I0aa68454b6c627c4d8b28812957bf5045504f461
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/235158
Trust: Than McIntosh <thanm@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
6 files changed