syntax_data: {"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"s.dcx().span_bug(sp,"}]}
source_snippet:             s.dcx().span_bug(sp, "missing binding mode");
context_before:         self.pat_binding_modes().get(id).copied().unwrap_or_else(|| {
context_after:         })