hg: jdk/jdk14: 8235866: bump jtreg requiredVersion to 4.2b16

[igor.ignatyev at oracle.com]

Changeset: bce0cd152f61
Author:    iignatyev
Date:      2019-12-16 15:45 -0800
URL:       https://hg.openjdk.java.net/jdk/jdk14/rev/bce0cd152f61

8235866: bump jtreg requiredVersion to 4.2b16
Reviewed-by: dholmes, joehw

! test/hotspot/jtreg/TEST.ROOT
! test/jaxp/TEST.ROOT
! test/jdk/TEST.ROOT
! test/langtools/TEST.ROOT
! test/nashorn/TEST.ROOT