[PMC] Plugged a memory leak related to the constant STRING contained in a constant String PMC workaround when thawing said constant String PMC from bytecode.  Hopefully this doesn't make inheriting from the String PMC problematic -- if there are any problems with HLLs and bytecode, this commit is a likely culprit.
[PMC] Plugged a memory leak related to the constant STRING contained in a
constant String PMC workaround when thawing said constant String PMC from
bytecode.  Hopefully this doesn't make inheriting from the String PMC
problematic -- if there are any problems with HLLs and bytecode, this commit is
a likely culprit.

Parrot now leaks no memory for "Hello, world!" written in PIR as well as PBC.

git-svn-id: 6e74a02f85675cec270f5d931b0f6998666294a3@39080 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

fernandobrito/parrot,youprofit/parrot,fernandobrito/parrot,fernandobrito/parrot,gagern/parrot,tkob/parrot,fernandobrito/parrot,gitster/parrot,tewk/parrot-select,FROGGS/parrot,tkob/parrot,tkob/parrot,tewk/parrot-select,youprofit/parrot,tkob/parrot,parrot/parrot,gitster/parrot,youprofit/parrot,fernandobrito/parrot,tkob/parrot,gitster/parrot,gagern/parrot,youprofit/parrot,tewk/parrot-select,gitster/parrot,FROGGS/parrot,gagern/parrot,youprofit/parrot,gitster/parrot,tewk/parrot-select,fernandobrito/parrot,youprofit/parrot,tewk/parrot-select,tewk/parrot-select,youprofit/parrot,parrot/parrot,FROGGS/parrot,gagern/parrot,FROGGS/parrot,fernandobrito/parrot,tkob/parrot,gagern/parrot,gagern/parrot,tkob/parrot,FROGGS/parrot,parrot/parrot,youprofit/parrot,gitster/parrot,tewk/parrot-select,parrot/parrot,gitster/parrot,FROGGS/parrot,gagern/parrot,parrot/parrot,FROGGS/parrot,FROGGS/parrot,tkob/parrot