Implement map/coerce for IntMap

[treeowl]

I realized what I was doing with MIN_VERSION was kind of silly.
The easy/sane thing to do is really to use GLASGOW_HASKELL
for the coercion stuff.

[foxik]

Thanks :-) If we are going to use __GLASGOW_HASKELL__ for coercion stuff (which we probably should), could you please also add commits which replace MIN_VERSION_base(4,8,0) in Map.Base, Map.Strict, Sequence and Tree?

[treeowl]

Yes, of course. I was planning to do that in a separate pull request.

[foxik]

I probably misunderstand your comment -- even though you "planned to do that in a separate pull request", I thought you will add the changes here, but you are probably waiting for me to merge this and want to do it later.

I am merging now, but leaving this pull request open to remind me that __GLASGOW_HASKELL__ and coercion still need to be sorted.

Thank you very much for all your work on containers!

[foxik]

It seems I cannot keep pull request opened after merging. Moving the remainder to a corresponding issue.

[treeowl]

Yes, my git-fu is very weak; I didn't want to try figuring out how to add commits to a pull request or whatever. I should definitely be able to put together a new one today.

[foxik]

Thanks :-)