Share unix getexepath() definition via src/native

[am11]

Deduplicate implementations via a new shared location; src/native/common.

cc @janvorli, @jkotas

[Dotnet-GitSync-Bot]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[am11]

Remove unixcoreruncommon static lib dependency 04283a3

@jkotas, now that coreconsole is deleted, the only consumer of unixcoreruncommon static lib is unixcorerun. I was thinking about merging these two projects in a separate PR, but since we need the definition of HAVE_GETAUXVAL (fast path) in unixcorerun.cpp (instead of unixcoreruncommon.cpp) as part of this PR, I have merge it here; one less shared lib / .a (archive) to worry about. :)

[janvorli]

LGTM, thank you! I really appreciate all the improvements that you are making in the .NET!

[ghost]

Hello @janvorli!

Because this pull request has the auto-merge label, I will be glad to assist with helping to merge this pull request once all check-in policies pass.

p.s. you can customize the way I help with merging this pull request, such as holding this pull request until a specific person approves. Simply @mention me (@msftbot) and give me an instruction to get started! Learn more here.

[janvorli]

The failures are unrelated, but the libraries tests were timing out, so we don't know their outcome. I think the cause for that timeout was fixed, so let me try to re-run the runtime tests one more time. I'll merge the change if the timeout issue is still there.

[am11]

Thanks. Libraries Test Run release coreclr Linux x64 Debug) failure is #45204.

[am11]

Thank you for the reviews, @janvorli. Much appreciate your thoughts with many learning points everytime! 👍