[bug] The operation cache does not propagate correctly on if else braches

[JeanJPNM]

In the following example we can see that the assignment to a in the if branch prevents the else branch from reusing the cached operation a + 1.

let a = Math.rand(10)

print(a + 1)

if (a > 5) {
  a = 2
} else {
  print(a + 1)
}

printFlush()

Output:

op rand &t0 10
op floor a:1:4 &t0
op add &t1 a:1:4 1
print &t1
jump 7 lessThanEq a:1:4 5
set a:1:4 5
jump 9 always
op add &t2 a:1:4 1
print &t2
printflush message1

Version: latest (cd75edd)