[OO] Reduced the amount of work required to get an attribute's index in the Object PMC.  This is a modest optimization (measurable, but not huge).
[OO] Reduced the amount of work required to get an attribute's index in the
Object PMC.  This is a modest optimization (measurable, but not huge).

git-svn-id: 6e74a02f85675cec270f5d931b0f6998666294a3@39185 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

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