fails:Enumerable#grep grep without a block should return an array of all elements === pattern
fails:Enumerable#grep grep with a block should return an array of elements === pattern passed through block
fails:Enumerable#grep grep the enumerable (rubycon legacy)
fails:Enumerable#grep can use $~ in the block when used with a Regexp
fails:Enumerable#grep calls the block with an array when yielded with multiple arguments
