Optimize jumps to unconditional jumps

When we have code like this, `jmp L1` should be changed to `jmp L2`:
```asm
jmp L1
...
L1:
jmp L2
...
L2:
```

This can happen for multiple hops as long as the jump is unconditional.

Original jump can conditional so this is also optimizable:
```asm
test rax, rax
je L1
...
L1:
jmp L2
...
L2:
```