Use (actually) dummy place for let-else divergence

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -2334,7 +2334,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         // This place is not really used because this destination place
         // should never be used to take values at the end of the failure
         // block.
-        let dummy_place = Place { local: RETURN_PLACE, projection: ty::List::empty() };
+        let dummy_place = self.temp(self.tcx.types.never, else_block.span);
         let failure_block;
         unpack!(
             failure_block = self.ast_block(

src/test/ui/let-else/issue-100103.rs

@@ -0,0 +1,15 @@
+// edition:2021
+// check-pass
+
+#![feature(try_blocks)]
+#![feature(let_else)]
+
+fn main() {
+    let _: Result<i32, i32> = try {
+        let Some(x) = Some(0) else {
+            Err(1)?
+        };
+
+        x
+    };
+}