Confusing variable names in error messages of the (S)CT checkers

[vbgl]

Here is an example of an insecure program:

inline fn f(reg u64 y x) {
  if y == x {
  }
}

export fn noct(#secret reg u64 x) {
  f(x, 0);
}

When running the CT checker on it after the rmphi pass (e.g., using jazzct --after=rmphi notct.jazz), it produces the following message:

"notct.jazz", line 2 (5-6):
constant type checker: x has type secret it needs to be public

Of course, x here refers to the parameter y of function f…