Revert of Steps towards unification of number bitset and range types. (patchset #4 id:60001 of https://codereview.chromium.org/837723006/)

Reason for revert:
Breaks test-types/Maybe, i.e.

out/Release/cctest --random-seed=-707413401 test-types/Maybe

started failing afterwards

Original issue's description:
> Steps towards unification of number bitset and range types.
>
> - New invariant on union types: if the union has a range then the number
>   bits in the bitset must be cleared.
>
> - Various tweaks in intersection and union to satisfy the invariant.
>
> - Exposed and used representation bits in range types (and the Limits
>   helper class).
>
> - Implemented Glb for ranges so that the Is predicate handles
>   ranges correctly.
>
> - Change typer weakening so that it does not rely on GetRange.
>   However, the code still seems to be a bit fragile.
>
> - Removed the Smi types from the type system core, instead introduced
>   Signed31, Unsigned30 and created constructors for Small(Un)Signed
>   that point to the right type for the architecture.
>
> - Punched a hole in the config to be able to get to the isolate so
>   that it is possible to allocate heap numbers for newly created
>   ranges.
>
> Patch by jarin@chromium.prg, original review here:
> https://codereview.chromium.org/795713003/
>
> TBR=jarin@chromium.org
> BUG=
>
> Committed: https://crrev.com/2764fd8d1a266a9136c987c2483492113b0c8d80
> Cr-Commit-Position: refs/heads/master@{#26197}

TBR=jkummerow@chromium.org,rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/868583002

Cr-Commit-Position: refs/heads/master@{#26207}