The changes in `GHC.Utils.Outputable` are the bulk of the patch
and drive the rest.
The types `HLine` and `HDoc` in Outputable can be used instead of `SDoc`
and support printing directly to a handle with `bPutHDoc`.
See Note [SDoc versus HDoc] and Note [HLine versus HDoc].

The classes `IsLine` and `IsDoc` are used to make the existing code polymorphic
over `HLine`/`HDoc` and `SDoc`. This is done for X86, PPC, AArch64, DWARF
and dependencies (printing module names, labels etc.).

Co-authored-by: Alexis King <lexi.lambda@gmail.com>

Metric Decrease:
    CoOpt_Read
    ManyAlternatives
    ManyConstructors
    T10421
    T12425
    T12707
    T13035
    T13056
    T13253
    T13379
    T18140
    T18282
    T18698a
    T18698b
    T1969
    T20049
    T21839c
    T21839r
    T3064
    T3294
    T4801
    T5321FD
    T5321Fun
    T5631
    T6048
    T783
    T9198
    T9233