[Ping] Port of VTV for Cygwin and MinGW

[Jonathan Wakely]

On 29/01/15 19:05 +0100, Matthias Klose wrote:
>that fixes the build failure. ok to commit?
>
>2015-01-29  Matthias Klose  <doko@ubuntu.com>
>
>        * acinclude.m4 (GLIBCXX_ENABLE_VTABLE_VERIFY): Define VTV_CYGMIN
>        unconditionally.
>        * configure: Regenerate.

OK, thanks.