syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"\"`ConstEquate`"}]}
source_snippet:                         "`ConstEquate` without a feature gate: {c1:?} {c2:?}",
context_before:                         tcx.features().generic_const_exprs(),
context_after:                     );