Surface errors from regal.parse_module in regal test output

[anderseknert]

It is quite common to have simple mistakes in the policy provided lead to silent failures, and these can be really tedious to debug. It's hard to think of any scenario where you would not want regal.parse_module to fail with a message (the parse error). I'm not sure if it's possible to run something like --strict-builtin-errors but only for selected functions, but something like that would be ideal.