EPA: Additional EPA backports needed for GHC 9.10

These additional commits are based on comparing current master and wip/ghc-9.10. This branch (wip/az/ghc-9.10-epa-additional-backports) compiles with ghc-exactprint and passes its tests, bar 2 known failures based on CPP comment management.

From my perspective, this makes GHC 9.10 release good to go for ghc-exactprint