[MERGE][1.15.1] use zdll on Windows to build chk_map extension

[Bundle Buggy]

Bundle Buggy has detected this merge request.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3Ch06a8r%24v7c%241%40ger.gmane.org%3E
Project: Bazaar