syntax_data: {"ast_node_type":"other","tokens":[{"end":24,"kind":"keyword","start":0,"text":"($lint:tt)"}]}
source_snippet:         ($lint:tt) => {{
context_before:     macro_rules! emit_diag {
context_after:             tcx.emit_node_span_lint(IRREFUTABLE_LET_PATTERNS, id, span, $lint { count });