syntax_data: {"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"debug_assert_eq!(pat.span.desugaring_kind(),"}]}
source_snippet:                 debug_assert_eq!(pat.span.desugaring_kind(), Some(DesugaringKind::ForLoop));
context_before:                 // `pat` should be `Some(<pat_field>)` from a desugared for loop.
context_after:                 let PatKind::Variant { ref subpatterns, .. } = pat.kind else { bug!() };