'go get' will now check absolute paths without wildcards the same way
it checks relative paths. modload.DirImportPath may be used for both
without converting path separators.
Fixes #38038
Change-Id: I453299898ece58f3b5002a5e80021d6bfe815fdd
Reviewed-on: https://go-review.googlesource.com/c/go/+/226857
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com> Reviewed-by: Michael Matloob <matloob@golang.org>