Go exchanges siginfo and sigevent structures with the kernel. They
contain unions, but Go's use is limited to the first few fields. Pad out
the rest so the size Go sees is the same as what the Linux kernel sees.
This is a follow-up to CL 342052 which added the sigevent struct without
padding. It updates the siginfo struct as well so there are no bad
examples in the defs_linux_*.go files.
Change-Id: Id991d4a57826677dd7e6cc30ad113fa3b321cddf
Reviewed-on: https://go-review.googlesource.com/c/go/+/353136
Run-TryBot: Rhys Hiltner <rhys@justin.tv>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Knyszek <mknyszek@google.com>