os: explain ProccessState.Exited() SIGKILL interaction
When a process is forcefully killed (for example, with SIGKILL on unix), its ProccessState.Exited() will return false.
Change-Id: I8cebc8d28f2ba1b687c145f6d941647fc3a10665
GitHub-Last-Rev:
414ae1980fe61dd530c46cc2c7f4de3a5bc83ed5
GitHub-Pull-Request: golang/go#48871
Reviewed-on: https://go-review.googlesource.com/c/go/+/354698
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Alexander Rakoczy <alex@golang.org>
Run-TryBot: Alexander Rakoczy <alex@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>