bug#11378: 24.1.50; Suggestion: Let M-i in isearch cycle `search-invisible'

[Drew Adams]

> It would be more useful to allow multiple filters by transforming
> `isearch-filter-predicate' from the variable defining a 
> predicate to the
> hook-like list defining a set of predicates all of which 
> should satisfy for the search hit.
> 
> The default value could be a list with the current default element
> `isearch-filter-visible'.  And it still could allow a symbol 
> as its value for backward compatibility.

+1