reinstating ignore-plugins-ghc-bounds

[GuillaumedeVolpiano]

Seen from Gentoo, the ignore-plugins-ghc-bounds is useful, this patch tries to make it do something again.

gentoo-haskell/gentoo-haskell#1766

[fendor]

LGTM!

I couldn't 100% tell from the discussion, does the Gentoo project have a particular use-case for this flag?

[GuillaumedeVolpiano]

Yep, the discussion was not very clear, but given the way ebuilds are structured, we need the same ebuild for every version of ghc (with a way of filtering plugins based on the version of ghc at the ebuild level). So basically, we pass the ignore-plugins-ghc-bounds so that these don’t interfere with our own filtering. Not sure I’m very clear.
Also, given the very nature of the distro (and our propension to patch things to make them work if they don’t), what actually works for us might be slightly different from the general use case: I’m still testing, but it seems that we have floskell working with ghc-9.12 here. So our filtering might be slightly different from yours.

Thanks for approving!