podcheck.t: Output fixed problems as passing to-do tests
pp_hot.c: Correct comment

At this point, ob holds the object the reference points to, not the
reference itself.
Flush PL_stashcache on glob-to-glob assignment

Commit dc93d7fb33f6b2093 says this:

    Flush PL_stashcache when assigning a file handle to a typeglob.

    File handles take priority over stashes for method dispatch.
    Assigning a file handle to a typeglob potentially creates a file
    handle where one did not exist before.  As PL_stashcache only con-
    tains entries for names which unambiguously resolve to stashes,
    such a change may mean that PL_stashcache now contains an invalid
    entry.  As it’s hard to work out exactly which entries might be
    affected, simply flush the entire cache and let it rebuild itself.

But it only applied to io-to-glob assignment.  This commit extends it
to glob-to-glob assignment.
File::Spec::Epoc: Small pod clean-up
[perl #89940] File::Spec->tmpdir and env changes

If the environment changes, File::Spec->tmpdir should respect that and
recalculate the temp directory.

The only objection raised in the ticket was that File::Spec is already
accused of being too slow, so removing the cache would not be a good
idea.  So I put in a check to see whether the relevant environment
variables have changed since the last call to tmpdir.
Correct File::Spec POD about tainting and tmpdir

Since version 3.39_01, the taint check has applied before 5.8.0, too.
Increase some File::Spec versions to 3.41