Review Request: 8006074: build-infra: Configure fails to find SetEnv.Cmd in microsoft sdk

[Erik Joelsson]

This small patch fixes a problem with configure, Cygwin and Microsoft 
SDK SetEnv.Cmd as reported in this mail:

http://mail.openjdk.java.net/pipermail/build-infra-dev/2013-January/002911.html
http://cr.openjdk.java.net/~erikj/8006074/webrev.root.01/