reverse package:ghc

Reverse the order of error messages in GHC/GHCi

If we've compute liveness info for this code already we have to reverse the SCCs in each top to get them back to the right order so we can do it again.

Make a bitmap where the slots specified are the zeros in the bitmap. eg. [0,1,3], size 4 ==> 0x4 (we leave any bits outside the size as zero, just to make the bitmap easier to read). The list of Ints must be already sorted and duplicate-free.

Reverse error reporting order