syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":".struct_span_err(sp,"}]}
source_snippet:             .struct_span_err(sp, "mismatched function ABIs")
context_before:             .dcx()
context_after:             .with_note("`become` requires caller and callee to have the same ABI")