syntax_data: {"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // are control points that we replace before printing with a visible codepoint for the sake
context_before:         // Keep the following list in sync with `rustc_errors::emitter::OUTPUT_REPLACEMENTS`. These
context_after:         // of being able to point at them with underlines.