clang-format: [Java] Support enums without trailing semicolon.

Before:
  class SomeClass {
    enum SomeThing { ABC, CDE } void f() {
    }
  }

After:
  class SomeClass {
    enum SomeThing { ABC, CDE }
    void f() {
    }
  }

This fixed llvm.org/PR21458.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221113 91177308-0d34-0410-b5e6-96231b3b80d8