hg: openjfx/jfx-dev/rt: 8222036: antlr generated files written to wrong location on Windows

[kevin.rushforth at oracle.com]

Changeset: 7fc05179c7db
Author:    kcr
Date:      2019-04-08 12:55 -0700
URL:       http://hg.openjdk.java.net/openjfx/jfx-dev/rt/rev/7fc05179c7db

8222036: antlr generated files written to wrong location on Windows
Reviewed-by: arajkumar, mennen

! build.gradle