hg: openjfx/jfx-dev/rt: 8213619: Windows powershell build script missing environment variables

[kevin.rushforth at oracle.com]

Changeset: f79cccd8514d
Author:    kcr
Date:      2018-11-14 13:02 -0800
URL:       http://hg.openjdk.java.net/openjfx/jfx-dev/rt/rev/f79cccd8514d

8213619: Windows powershell build script missing environment variables
Reviewed-by: kcr, mennen
Contributed-by: wookey.dean at gmail.com

! tools/scripts/build.ps1