With the removal of HHVM support, we can now use explicit varargs
in function arguments. This patch updates the PPFrame interface to
do so, and also removes PhanCommentParamWithoutRealParam check suppressions,
which are now redundant.
It seems that classes implementing this interface were already using varargs.
Bug: T231710
Change-Id: Ib1d69575835df80dca4e43b0028ad9368f62bb58