RFR: JDK-8203795: Change default compiler on Windows to VS2017

[Erik Joelsson]

Now that we have support for building with VS2017, it's time to change 
the default compiler picked up by the configure script to VS2017.

Oracle is also changing the version used internally, by updating 
jib-profiles.js

Webrev: http://cr.openjdk.java.net/~erikj/8203795/webrev.01/

Bug: https://bugs.openjdk.java.net/browse/JDK-8203795

/Erik