Make sure we still perform a zpp check for the static case, and
also always enforce that the parameter is ?object. Otherwise we
violate the specified signature.
PHP requires boolean typehints to be written "bool" and disallows
"boolean" as an alias. This changes the error messages to match
the actual type name and avoids confusing messages like "must be
of type boolean, boolean given".
This a followup to ce1d69a1f6, which
implements the same change for integer->int.