syntax_data: {"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // If it looks like a width, try to be helpful.
context_before:             if looks_like_width_suffix(&['i', 'u'], suf) {
context_after:                 dcx.emit_err(InvalidIntLiteralWidth { span, width: suf[1..].into() })