It will use the full names that appear in netbsd's /usr/include/sys/syscall.h names.
This adds some compat-goo (sys_sigprocmask->SYS_sigprocmask14), which might not be pretty, but the information about whether the compat version is used is probably important, as Go will keep using interfaces even after they are considered compatibility, which has caused problems in the past.
also, the same names appear in ktrace (with the numbers).

Change-Id: Idc1bb254ee33757a39ba224d91e8fbb0331e2149
GitHub-Last-Rev: b915e8f8a323cdc2d03119c3cf18e35d08c63d18
GitHub-Pull-Request: golang/go#31594
Reviewed-on: https://go-review.googlesource.com/c/go/+/173158Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>