syntax_data: {"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":".struct_span_err(sp,"}]}
source_snippet:             .struct_span_err(sp, "c-variadic functions can't be tail-called")
context_before:             // FIXME(explicit_tail_calls): highlight the function or something...
context_after:             .emit();