syntax_data: {"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:         if let LetSource::PlainLet = self.let_source {
context_before:         let scrut = scrutinee.map(|id| &self.thir[id]);
context_after:             self.check_binding_is_irrefutable(pat, "local binding", scrut, Some(span))