feat(tazjin/rlox): Implement else clauses

Change-Id: I0bc2333c0b4dd3e2e584a90d0d15b28c48130f03
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3740
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>

users/tazjin/rlox/src/bytecode/vm.rs

@@ -213,6 +213,10 @@ impl VM {
                     panic!("unpatched jump detected - this is a fatal compiler error!");
                 }
 
+                OpCode::OpJump(offset) => {
+                    self.ip += offset.0;
+                }
+
                 OpCode::OpJumpIfFalse(offset) => {
                     if self
                         .stack