Bug 1057224 - Pass actual class name for rdf ctor counting. r=nfroydnj

We want to enforce valid names in these macros, so we need
to use a valid type name here.
Bug 1057224 - Assert that MOZ_COUNT_* are passed a class name. r=ehsan

This helps detect typos, which lead to undetected or spurious
leaks in the leak check.