[perl #39329] Check to make sure PMC_str_val, etc. are used appropriately

I think this ticket is ready to be closed.  A lot of the PMC_* items
were likely fixed as part of the pdd15oo change, and the problem I cited
has apparently been fixed.

Pm

• [perl #39329] Check to make sure PMC_str_val, etc. are used appropriately by Patrick R. Michaud via RT
• Re: [perl #39329] Check to make sure PMC_str_val, etc. are used appropriately by Patrick R. Michaud