Do not ICE on pattern that uses a binding multiple times in generator

compiler/rustc_typeck/src/check/generator_interior.rs

@@ -250,10 +250,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InteriorVisitor<'a, 'tcx> {
             let mut scope_var_ids =
                 self.guard_bindings.pop().expect("should have pushed at least one earlier");
             for var_id in scope_var_ids.drain(..) {
-                assert!(
-                    self.guard_bindings_set.remove(&var_id),
-                    "variable should be placed in scope earlier"
-                );
+                self.guard_bindings_set.remove(&var_id);
             }
         }
         self.visit_expr(body);

src/test/ui/issues/issue-78115.rs

@@ -0,0 +1,19 @@
+// Regression test for issue #78115: "ICE: variable should be placed in scope earlier"
+
+// check-pass
+// edition:2018
+
+#[allow(dead_code)]
+struct Foo {
+    a: ()
+}
+
+async fn _bar() {
+    let foo = Foo { a: () };
+    match foo {
+        Foo { a: _a } | Foo { a: _a } if true => {}
+        _ => {}
+    }
+}
+
+fn main() {}