RFR 8215702: SVG gradients are not rendered

[Arunprasad Rajkumar]

Hi,

Please review the following PR related to JDK-8215702,

https://github.com/javafxports/openjdk-jfx/pull/347

https://bugs.openjdk.java.net/browse/JDK-8215702

Thanks,
Arun