clang/win: Disable -Wexit-time-destructors for now.

I'm not 100% sure this will be evaluated at the right time to have an effect.

BUG=404525
TBR=hans@chromium.org

Review URL: https://codereview.chromium.org/481823002

Cr-Commit-Position: refs/heads/master@{#290208}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@290208 0039d316-1c4b-4281-b951-d872f2087c98

build/common.gypi

@@ -5406,6 +5406,7 @@
                   '-Wno-unused-private-field',
                   '-Wno-unused-value',
                   '-Wno-unused-variable',
+                  '-Wno-exit-time-destructors',  # TODO: http://crbug.com/404525
                   '-ferror-limit=1',
                 ],
               },