Revert of [stubs] Don't unconditionally canonicalize in ChangeFloat64ToTagged. (patchset #2 id:20001 of https://codereview.chromium.org/2380543002/ )

Reason for revert:
Tanks ai-astar in Kraken pretty badly (some deopt loop).

Original issue's description:
> [stubs] Don't unconditionally canonicalize in ChangeFloat64ToTagged.
>
> Add a CanonicalizationMode to CodeStubAssembler::ChangeFloat64ToTagged,
> so clients can request Smi canonicalization when desired, but otherwise
> get Crankshaft/Fullcodegen compatible behavior of just boxing the double
> into a HeapNumber.
>
> R=verwaest@chromium.org
> BUG=v8:5268
>
> Committed: https://crrev.com/06eef6e6d8199df8317df8469d767092472f3fe0
> Cr-Commit-Position: refs/heads/master@{#39804}

TBR=verwaest@chromium.org,jarin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5268

Review-Url: https://codereview.chromium.org/2373253003
Cr-Commit-Position: refs/heads/master@{#39812}