[11u] RFR: 8232167: Visual Studio install found through --with-tools-dir value is discarded

[Langer, Christoph]

Hi,

please review this simple backport of a simple build system fix which unfortunately did not apply cleanly. It's just context changes that needed to be resolved. I ran into this with jdk11u after I reinstalled my Visual Studio to a non-default folder and used configure option --with-tools-dir. So it should be backported.

Bug: https://bugs.openjdk.java.net/browse/JDK-8232167
Original change: https://hg.openjdk.java.net/jdk/jdk/rev/5a4b4544b810
Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8232167.11u/

Thanks
Christoph