https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63459
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- I think a method call always has this != NULL so you'd infer this != NULL after the call with a ASSERT_EXPR. With the pattern stuff you can't really write "any call with some nonnull attribute on it" so you need a tree predicate for this.
