Bug#893244: jruby FTBFS with openjdk-9

[Adrian Bunk]

Source: jruby
Version: 9.1.13.0-1
Severity: serious

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/jruby.html

...
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /build/1st/jruby-9.1.13.0/core/src/main/java/org/jruby/management/BeanManagerImpl.java:[87,26] error: cannot find symbol
  symbol:   class Agent
  location: package sun.management