syntax_data: {"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"Diag::new(dcx,"}]}
source_snippet:             Diag::new(dcx, level, fluent::mir_build_non_exhaustive_patterns_type_not_empty);
context_before:         let mut diag =
context_after:         diag.span(self.scrut_span);