Incorrect mutation of direct initialization with comma

[JamesLee-Jones]

Dredd incorrectly mutates direct initialization of variables using the comma operator. The following:

int main() {
  int b((1,0));
}

Gets mutated to:

# Dredd prelude
int main() {
  int b((__dredd_replace_expr_int_zero(__dredd_replace_expr_int_one(1, 0),__dredd_replace_expr_int_zero(0, 3), 5)));
}

This leads __dredd_replace_expr_int_zero take in three arguments when it should only take in two.