FAIL_IF_MINUS_ONE was checking if arg != 0, which is FAIL_IF_NONZERO. I changed that to == -1 as it should be.

Also, I added parenthesis guards for the arguments, without them, the macro contains subtle bugs: for example the conditional in FAIL_IF_MINUS_ONE(1 | 0) evaluated to true even though 1 | 0 evaluates to 1 which is not equal to -1:
Before:

1 | 0 == -1    ===>    1 | (0 == -1)    ===>    1 | 0    ===>    1 (true!)

After:

(1 | 0) == -1    ===>   0 == -1    ===>    0 (false)