Add 82981

May not be that important, due to the use of a perma-unstable attribute.

Issue: rust-lang/rust#82981

Author: fanninpm

ices/82981.rs

@@ -0,0 +1,5 @@
+#![crate_type = "staticlib"]
+#![feature(rustc_attrs)]
+#[rustc_layout_scalar_valid_range_start(A)]
+struct T {}
+const C: T = T {};