syntax_data: {"ast_node_type":"other","tokens":[{"end":27,"kind":"keyword","start":0,"text":"scrut_ty:"}]}
source_snippet:         scrut_ty: Ty<'tcx>,
context_before:         arms: &[MatchArm<'p, 'tcx>],
context_after:     ) -> Result<UsefulnessReport<'p, 'tcx>, ErrorGuaranteed> {