syntax_data: {"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"arg"}]}
source_snippet:                         arg = self.thir.exprs.push(Expr {
context_before:                             .temporary_scope(self.region_scope_tree, arg_expr.hir_id.local_id);
context_after:                             temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },