EUV: fix place of deref pattern's interior's scrutinee

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -1840,7 +1840,8 @@ impl<'tcx, Cx: TypeInformationCtxt<'tcx>, D: Delegate<'tcx>> ExprUseVisitor<'tcx
                 let ty = self.pat_ty_adjusted(subpat)?;
                 let ty = Ty::new_ref(self.cx.tcx(), re_erased, ty, mutability);
                 // A deref pattern generates a temporary.
-                let place = self.cat_rvalue(pat.hir_id, ty);
+                let base = self.cat_rvalue(pat.hir_id, ty);
+                let place = self.cat_deref(pat.hir_id, base)?;
                 self.cat_pattern(place, subpat, op)?;
             }
 

tests/ui/pattern/deref-patterns/dont-ice-on-slice-in-deref-pat-in-closure.rs

@@ -0,0 +1,15 @@
+//@ check-pass
+//! Regression test for ICE in `rustc_hir_typeck::expr_use_visitor` on nesting a slice pattern
+//! inside a deref pattern inside a closure: rust-lang/rust#125059
+
+#![feature(deref_patterns)]
+#![allow(incomplete_features, unused)]
+
+fn simple_vec(vec: Vec<u32>) -> u32 {
+   (|| match Vec::<u32>::new() {
+        deref!([]) => 100,
+        _ => 2000,
+    })()
+}
+
+fn main() {}