syntax_data: {"ast_node_type":"other","tokens":[{"end":49,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // Checks if `s` looks like i32 or u1234 etc.
context_before: ) -> ErrorGuaranteed {
context_after:     fn looks_like_width_suffix(first_chars: &[char], s: &str) -> bool {