syntax_data: {"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // be replaced with `false`.
context_before:                 // coinductive, but GCE is on the way out anyways, so this should eventually
context_after:                 self.infcx.tcx.features().generic_const_exprs()