[PATCH] Don't allow dllimport variables in constant initializers

[Hans Wennborg]

On Wed, Jun 25, 2014 at 5:01 PM, Reid Kleckner <rnk at google.com> wrote:
> This seems problematic for mingw, where I expect users probably use non-type template parameters of dllimported stuff.  Is there another way we can handle this?

David did a better fix in r211766, which makes us allow dllimport
template arguments for mingw too.