Refactor Unique to be represented by Word64

In #22010 we established that Int was not always sufficient to store all
the uniques we generate during compilation on 32-bit platforms. This
commit addresses that problem by using Word64 instead of Int for
uniques.

The core of the change is in GHC.Core.Types.Unique and
GHC.Core.Types.Unique.Supply. However, the representation of uniques is
used in many other places, so those needed changes too. Additionally, the RTS
has been extended with an atomic_inc64 operation.

One major change from this commit is the introduction of the Word64Set and
Word64Map data types. These are adapted versions of IntSet and IntMap
from the containers package. These are planned to be upstreamed in the
future.

As a natural consequence of these changes, the compiler will be a bit
slower and take more space on 32-bit platforms. Our CI tests indicate
around a 5% residency increase.

Metric Increase:
    CoOpt_Read
    CoOpt_Singletons
    LargeRecord
    ManyAlternatives
    ManyConstructors
    MultiComponentModules
    MultiComponentModulesRecomp
    MultiLayerModulesTH_OneShot
    RecordUpdPerf
    T10421
    T10547
    T12150
    T12227
    T12234
    T12425
    T12707
    T13035
    T13056
    T13253
    T13253-spj
    T13379
    T13386
    T13719
    T14683
    T14697
    T14766
    T15164
    T15703
    T16577
    T16875
    T17516
    T18140
    T18223
    T18282
    T18304
    T18698a
    T18698b
    T18923
    T1969
    T19695
    T20049
    T21839c
    T3064
    T3294
    T4801
    T5030
    T5321FD
    T5321Fun
    T5631
    T5642
    T5837
    T6048
    T783
    T8095
    T9020
    T9198
    T9233
    T9630
    T9675
    T9872a
    T9872b
    T9872b_defer
    T9872c
    T9872d
    T9961
    TcPlugin_RewritePerf
    UniqLoop
    WWRec
    hard_hole_fits