Two new draft pattern matching JEPs

[Gavin Bierman]

Dear all,

The next steps in adding pattern matching to Java are coming! I have drafted two new JEPs:

- Nested Record and Array Patterns: https://bugs.openjdk.java.net/browse/JDK-8260244

- Pattern Matching for switch: https://bugs.openjdk.java.net/browse/JDK-8213076

We split them up to try to keep the complexity down, but we might decide to merge them into a single JEP. Let me know what you think. 

Draft language specs are under way - I will announce those as soon as they are ready.

Comments welcome as always!

Thanks,
Gavin