Implement BLTU

src/instructions.rs

@@ -52,6 +52,7 @@ pub(crate) fn find_and_exec(instr: Instruction, core: &mut Core) -> Option<Instr
             // BRANCH
             0b000 => Some(rvi::beq(core, instr)),
             0b001 => Some(rvi::bne(core, instr)),
+            0b110 => Some(rvi::bltu(core, instr)),
             0b111 => Some(rvi::bgeu(core, instr)),
             _ => None,
         },