Master test failing consistently for JDK 11

[Danny Chan]

Here is the link 
https://builds.apache.org/job/Calcite-Master/1414/jdk=JDK%2011%20(latest),label_exp=ubuntu&&!cloud-slave&&!H27&&!ubuntu-4/console

The fail case is: PigRelBuilderStyleTest.testImplWithGroupByCountDistinct

Best,
Danny Chan