cmd/go: include imports in 'go list -e' output even after parse errors
If we aren't able to load imports from one file in a package due to a
parse error (scanner.ErrorList), 'go list -e' should still list
imports in other files.
Fixes #35973
Change-Id: I59f171877949bb7afaf252b6c8a970de22e60c7a
Reviewed-on: https://go-review.googlesource.com/c/go/+/210097
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>