clang/win: Disable oilpan plugin on 64-bit builds again.

clang/win: Disable oilpan plugin on 64-bit builds again.

This reverts https://codereview.chromium.org/1136943002
for 64-bit builds.

There are many [blink-gc] warnings from the oilpan plugin at the moment,
and the 64-bit bots build with warnings as errors.  Disable the plugin on
64-bit builds to keep the bots green until they're fixed.

BUG=486571, 467287
TBR=hans

Committed: https://chromium.googlesource.com/chromium/src/+/18e6597a4d62570d8a6831c1521a551e7af9b077

[Nico, 2015-05-11 01:15:15]

thakis@chromium.org changed reviewers:
+ hans@chromium.org

[commit-bot: I haz the power, 2015-05-11 01:22:20]

Patchset 1 (id:??) landed as
https://crrev.com/18e6597a4d62570d8a6831c1521a551e7af9b077
Cr-Commit-Position: refs/heads/master@{#329089}

[Nico, 2015-05-11 01:22:37]

Committed patchset #1 (id:1) manually as
18e6597a4d62570d8a6831c1521a551e7af9b077 (presubmit successful).

[Nico, 2015-05-17 19:22:34]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1131333003/ by thakis@chromium.org.

The reason for reverting is: [blink-gc] warnings are fixed, we can turn this on
again.