Some StringData* helpers were forwarding to CStrRef
methods - which now forward to StringData* methods. Just
call the StringData* methods directly
Other methods were using stack allocated StringData's.
Thats pointlessly risky for slow-path code. Use a String
instead.
This change is mostly for FB internal organizational reasons.
Building is not effected beyond the fact that the target now
lands in hphp/hhvm/hhvm rather than src/hhvm/hhvm.
mwilliams