[GC] After the mark phase of a GC run, sweep the STRING/Buffer pools too so that we can free allocated memory for string contents and reuse allocated headers.
[GC] After the mark phase of a GC run, sweep the STRING/Buffer pools too so
that we can free allocated memory for string contents and reuse allocated
headers.

Maybe our memory use will go down again now.

Fixes RT #47704, reported by Mehmet Yavuz Selim Soyturk.

git-svn-id: 6e74a02f85675cec270f5d931b0f6998666294a3@25633 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot