syntax_data: {"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"return"}]}
source_snippet:                     return self.mk_err(tcx.dcx().create_err(NaNPattern { span }), ty);
context_before:                     // Also see <https://github.com/rust-lang/rfcs/pull/3535>.
context_after:                 } else {