Make the gc.collect() function respect the collection lock.  This fixes SF bug 476129: "gc.collect sometimes hangs".
Make the gc.collect() function respect the collection lock.  This fixes
SF bug 476129: "gc.collect sometimes hangs".

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator