Behavior for method modifiers with non-regexp refs

Behavior for method modifiers with non-regexp refs

The code:
before ['foo', 'bar'] => sub { }
Was previously silently ignored. Now it means the same as:
before ('foo', 'bar') => sub { }

This means that method modifiers can now be:
* a list
* a regexp ref.
* an arrayref

Anything else results in an error message.