syntax_data: {"ast_node_type":"other","tokens":[{"end":29,"kind":"keyword","start":0,"text":"scrutinee_span:"}]}
source_snippet:         scrutinee_span: Span,
context_before:         fake_borrow_temps: &[(Place<'tcx>, Local, FakeBorrowKind)],
context_after:         arm_match_scope: Option<(&Arm<'tcx>, region::Scope)>,