clang/win plugin: Do not warn on dllexport inline move constructors.

clang/win plugin: Do not warn on dllexport inline move constructors.

This is like https://codereview.chromium.org/1129093002 , but for move
constructors instead of copy constructors.

Also add a test for https://codereview.chromium.org/1129093002 (and this).
Since testing dllexport on non-win requires a -target and can't depend on
system headers (windows system headers aren't installed where we run tests),
convert the test the new test was based on to be standalone (we should do
this for all tests, http://crbug.com/486559)

BUG=483986, 486559
Committed: https://crrev.com/130ce4bc6a38d2b4b904499c5e14db1841835c2a
Cr-Commit-Position: refs/heads/master@{#329208}

[Nico, 2015-05-10 22:51:59]

thakis@chromium.org changed reviewers:
+ dcheng@chromium.org, thakis@chromium.org

[Nico, 2015-05-10 22:54:00]

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

[Nico, 2015-05-10 22:54:01]

s/me/hans/ in reviewers (how did that happen??)

[Nico, 2015-05-11 01:16:15]

The CQ bit was checked by thakis@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-05-11 01:19:48]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1137973002/40001

[commit-bot: I haz the power, 2015-05-11 01:30:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-05-11 01:30:47]

Dry run: This issue passed the CQ dry run.

[hans, 2015-05-11 18:04:45]

lgtm

[Nico, 2015-05-11 18:05:12]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2015-05-11 18:11:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1137973002/40001

[commit-bot: I haz the power, 2015-05-11 18:47:37]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-05-11 18:49:26]

Patchset 3 (id:??) landed as
https://crrev.com/130ce4bc6a38d2b4b904499c5e14db1841835c2a
Cr-Commit-Position: refs/heads/master@{#329208}