Check for avoiding invalidating old dependencies on upgrades

[Kari Pahula <kaol@iki.fi>]

Hello.

I'd like to receive some comments about my patch to #170825 and
possibly have it merged.  Currently a package upgrade can invalidate a
dependency satisfied by the old version of the package but not the new
one.  I've added a check to catch this situation.

My AM asked to be CCd.

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