support ghc-flavor ghc-9.8.4

[shayne-fletcher]

• add support for ghc-9.8.4

  • this required replacing atomic_inc64 with atomic_inc in 'genSym.c' ((i) pre 9.8.4 RTS don't have atomic_inc64 (ii) atomic_inc did for 9.8.3 it will do here (iii) atomic_inc on 64-bit platforms appears equivalent in effect (iv) all of this is eliminated from 'genSym.c' in later versions of GHC)

• delete .github/workflows/ghc-9.8.2-ghc-9.6.5.yml and replace it with .github/workflows/ghc-9.8.4-ghc-9.6.5.yml

  • i expect because of this, the branch protection rules for this repository will need to be updated (the list of workflows that are required to run before merging) after merging this PR

• i also tweaked the filepath lower bounds in the 9.8 and 9.10 cases (making them more consistent with GHC)

[dylant-da]

LGTM, thank you for this!
I'll contact Richard on our end to ask about the workflow changes.

[dylant-da]

Looks like gitlab failed to resolve, possibly a flake, restarting

[shayne-fletcher]

@dylant-da

Looks like gitlab failed to resolve, possibly a flake, restarting

i just saw a post to the GHC Devs list about https://ghc.gitlab.haskell.org gives 502 bad gateway for Liquid Haskell so we are not the only project affected.