syntax_data: {"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // was actually computable (like if the `ty::Error` showed up only in a `PhantomData`).
context_before:     // The only side-effect of this is possibly worse diagnostics in case the layout
context_after:     if let Err(guar) = ty.error_reported() {