Revert of Debugger: deduplicate shared function info when setting script break points.

Revert of Debugger: deduplicate shared function info when setting script break points. (patchset #4 id:60001 of https://codereview.chromium.org/998253005/)

Reason for revert:
Code caching failures.

Original issue's description:
> Debugger: deduplicate shared function info when setting script break points.
>
> Also fix Debug.showBreakPoints for multiple break points at the same location.
>
> BUG=v8:3960
> LOG=N
>
> Committed: https://crrev.com/73b17a71a22564c0b66d9aa7c00948c748f5b290
> Cr-Commit-Position: refs/heads/master@{#27444}

TBR=mstarzinger@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3960
Committed: https://crrev.com/9b29d008dfcc00bf56be8040add1d2c5e404673b
Cr-Commit-Position: refs/heads/master@{#27448}

[Yang, 2015-03-25 15:18:46]

Created Revert of Debugger: deduplicate shared function info when setting script
break points.

[commit-bot: I haz the power, 2015-03-25 15:18:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/999273003/1

[commit-bot: I haz the power, 2015-03-25 15:19:12]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-25 15:19:30]

Patchset 1 (id:??) landed as
https://crrev.com/9b29d008dfcc00bf56be8040add1d2c5e404673b
Cr-Commit-Position: refs/heads/master@{#27448}

[Michael Starzinger, 2015-03-25 15:37:38]

LGTM (rubber-stamped).

[Yang, 2015-03-26 09:57:35]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1037013002/ by yangguo@chromium.org.

The reason for reverting is: Reland since the failure has been fixed in
https://codereview.chromium.org/1035523005/.