Add the files and decode logic for RVA

src/instructions/rva.rs

@@ -0,0 +1,14 @@
+// Copyright (c) 2026 taitep
+// SPDX-License-Identifier: BSD-2-Clause
+//
+// This file is part of TRVE (https://gitea.taitep.se/taitep/trve)
+// See LICENSE file in the project root for full license text.
+
+use super::illegal;
+use crate::{core::Core, decode::Instruction, exceptions::Exception};
+
+pub(super) fn find_and_exec(instr: Instruction, core: &mut Core) -> Result<(), Exception> {
+    match (instr.funct3(), instr.funct5()) {
+        _ => illegal(instr),
+    }
+}