cmd/viewcore: ignore mapped files without executable regions

[bozaro]

This change ignores files without executable regions to avoid errors on loading debug info from this files.

In our case we got confusing bad magic number errors on parsing files with GeoIP data.

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[gopherbot]

Message from Keith Randall:

Patch Set 1:

(2 comments)

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[gopherbot]

Message from Go Bot:

Patch Set 1:

Congratulations on opening your first change. Thank you for your contribution!

Next steps:
Within the next week or so, a maintainer will review your change and provide
feedback. See https://golang.org/doc/contribute.html#review for more info and
tips to get your patch through code review.

Most changes in the Go project go through a few rounds of revision. This can be
surprising to people new to the project. The careful, iterative review process
is our way of helping mentor contributors and ensuring that their contributions
have a lasting impact.

During May-July and Nov-Jan the Go project is in a code freeze, during which
little code gets reviewed or merged. If a reviewer responds with a comment like
R=go1.11, it means that this CL will be reviewed as part of the next development
cycle. See https://golang.org/s/release for more details.

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/232460.
After addressing review feedback, remember to publish your drafts!