Revert of [builtins] Introduce proper Float64Exp operator. (patchset #5 id:80001 of https://codereview.chromium.org/2077533002/ )

Reason for revert:
[Sheriff] Leads to some different rounding as it seems in some audio layout tests. Please rebase upstream first if intended:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/7508

Original issue's description:
> [builtins] Introduce proper Float64Exp operator.
>
> Import base::ieee754::exp() from FreeBSD msun and introduce a Float64Exp
> TurboFan operator based on that, similar to what we do for Float64Log.
> Rewrite Math.exp() as TurboFan builtin and use that operator to also
> inline Math.exp() into optimized TurboFan functions.
>
> BUG=v8:3266,v8:3468,v8:3493,v8:5086,v8:5108
> R=mvstanton@chromium.org
>
> Committed: https://crrev.com/93e26314afc9da9b5b8bd998688262444ed73260
> Cr-Commit-Position: refs/heads/master@{#37037}

TBR=mvstanton@chromium.org,ahaas@chromium.org,bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3266,v8:3468,v8:3493,v8:5086,v8:5108

Review-Url: https://codereview.chromium.org/2070813002
Cr-Commit-Position: refs/heads/master@{#37039}