This patch fixes a case where a path to a non directory can cause DirHash func to panic.

Fixes golang/go#57269

Change-Id: I743970dcafdf3bfee94baf4b714429a404decda9
GitHub-Last-Rev: a17ca1a
GitHub-Pull-Request: #16
Reviewed-on: https://go-review.googlesource.com/c/mod/+/457075
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Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
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This PR replaces the deprecated in Go 1.17 `io/ioutil` package with `io` and `os` packages.

Changes are the same as in [CL 430799](https://go.dev/cl/430799) but with test fixes.

Change-Id: I69095e5d62b10879fd273305876fd7498803705d
GitHub-Last-Rev: 28cdff9
GitHub-Pull-Request: #17
Reviewed-on: https://go-review.googlesource.com/c/mod/+/462278
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
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The "equivalent Unix command" was missing a layer of sha256sum.

Fixes golang/go#48498.

Change-Id: I1051bfa5fcbbf1625623d11cf21686b33da19b88
Reviewed-on: https://go-review.googlesource.com/c/mod/+/464295
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
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