Revert of [runtime] Change JavaScriptFrame::GetFunctions interface. (patchset #2 id:20001 of https://codereview.chromium.org/2626213002/ )

Reason for revert:
Breaks compilation.

Original issue's description:
> [runtime] Change JavaScriptFrame::GetFunctions interface.
>
> This adapts the aformentioned interface to no longer return a list of
> {JSFunction} objects, but {SharedFunctionInfo} objects instead. Since
> deoptimization data only contains the latter as literals, this by now
> represents the fast path. All call sites requiring the former can use
> the slow path via {JavaScriptFrame::Summarize} instead.
>
> R=jarin@chromium.org
>
> Review-Url: https://codereview.chromium.org/2626213002
> Cr-Commit-Position: refs/heads/master@{#42311}
> Committed: https://chromium.googlesource.com/v8/v8/+/25a9364f25a40986f4d7266b1fe53a5921754f6a

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

Review-Url: https://codereview.chromium.org/2629113004
Cr-Commit-Position: refs/heads/master@{#42312}