[release-branch.go1.18] cmd/go: prevent panic in go work use
Check if paths passed as arguments are existing directories.
Fixes #52140
Updates #51841
Change-Id: Icfd148627e6f2c4651d6f923a37d413e68c67f6c
GitHub-Last-Rev:
77fffa7635052f11dc93488ee23fd1c895284b4d
GitHub-Pull-Request: golang/go#51845
Reviewed-on: https://go-review.googlesource.com/c/go/+/394154
Trust: Bryan Mills <bcmills@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/397995
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>