[Bug 38713] Link failure due to use of libunwind in ntdll

https://bugs.winehq.org/show_bug.cgi?id=38713

Ken Thomases  changed:

What    |Removed                     |Added
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  Attachment #51676|0                           |1
        is obsolete|                            |

--- Comment #7 from Ken Thomases  ---
Created attachment 51677
  --> https://bugs.winehq.org/attachment.cgi?id=51677
configure check for libunwind

Oops.  Last attachment was a diff on top of Erich's.  Fixed to be a
self-contained patch.