SPDX-License-Identifier: MIT OR Apache-2.0

Replace the post-monomorphization "Leaked register!" const panic with an
empty drop.  OpenBSD ports build with panic=unwind, whose cleanup paths
instantiate Drop for LinearReg and make the const panic fire during
compilation.  The comment above the impl explicitly allows removing the
check when it produces false positives.

Index: interpreter/src/ir/lower/utils.rs
--- interpreter/src/ir/lower/utils.rs.orig
+++ interpreter/src/ir/lower/utils.rs
@@ -320,13 +320,7 @@ impl Drop for LinearReg {
 /// but assert _they are_; the rt fallback not catching them is not an excuse.
 #[cfg(not(debug_assertions))]
 impl Drop for LinearReg {
-    fn drop(&mut self) {
-        fn evil<T>() {
-            let _ = std::marker::PhantomData::<T>;
-            const { panic!("Leaked register!") }
-        }
-        evil::<()>();
-    }
+    fn drop(&mut self) {}
 }
 
 impl From<&LinearReg> for Reg {
