[BUG] [CLDR pattern] CLDR pattern lib can't be compiled with JDK11.

[lyiyu66]

Describe the bug CLDR pattern lib can't be compiled with JDK11.

To Reproduce Steps to reproduce the behavior:

1. Install jdk 11.0.13.
2. Download g11n-cldr-pattern branch code.
3. Compile it with command: gradle build
4. See error as below screenshot

Expected behavior CLDR pattern lib can be compiled successfully with JDK11.

Screenshots

Desktop (please complete the following information):

• OS: Windows 10