Make GVN dedup scalar constants

hercules_opt/src/gvn.rs

@@ -31,7 +31,10 @@ pub fn gvn(editor: &mut FunctionEditor, gvn_constants_and_clones: bool) {
             // Also, don't GVN constants and clones if indicated to not do so.
             if *number == work
                 || (!gvn_constants_and_clones
-                    && (editor.func().nodes[work.idx()].is_constant()
+                    && (editor.func().nodes[work.idx()]
+                        .try_constant()
+                        .map(|cons_id| !editor.get_constant(cons_id).is_scalar())
+                        .unwrap_or(false)
                         || editor.func().nodes[work.idx()]
                             .try_write()
                             .map(|(_, _, indices)| indices.is_empty())