[DynInst_API:] Please review coverity-driven fixes

[Josh Stone <jistone@xxxxxxxxxx>]

Hi,

I have published a batch of fixes for issues reported by Coverity:
https://sourceware.org/git/gitweb.cgi?p=dyninstfans.git;a=shortlog;h=refs/heads/jistone/coverity

I'd like to get these in before I disappear for the holiday, though I
may have already missed you reviewers departing. :)

The bulk of these fixes are for UNINIT_CTOR, i.e. POD-typed members that
are not initialized in the constructor or its callees.  There are a few
other logic errors fixed too, and a few things that just needed syntax
tweaks to avoiding getting flagged as a possible issue.

There's nothing too scary, I think.  I'd like to push this early next
week if there's no review blocker.

Thanks,
Josh