[FEATURE] JDK 17 support

[clemstoquart]

Hello lombok team,

JDK 17 release is just around the corner and it would be very convenient to have at least a lombok snapshot to start working on the migration.

Thanks !

[Rawi01]

Thanks for the reminder, release date for Java 17 is 2021-09-14.

So far I have identified these tasks:

• Support new switch expressions
• Support sealed classes
• Update ASM to 9.1+

I already started to fix the first switch expression related thing (https://github.com/Rawi01/lombok/tree/jdk-17).

[rzwitserloot]

An edge release is out with this patch applied. Give it a whirl if you like :)

https://projectlombok.org/download-edge

[chrisgleissner]

The edge release works well on a large project that uses most of Lombok's features. We had trouble with the @Singular annotation and slow val performance. Both are fixed as I verified on OpenJDK 11 and 17GA. We are keen to upgrade and hope that a new release can be cut soon.

[clemstoquart]

Hi,
I confirm that everything is now working fine with JDK 17 🎉

[rzwitserloot]

Weeeellll, time for us to start getting a new release out the door Real Soon Now. @Rawi01 deserves all the credit for making it work. @clemstoquart gracias for checking the edge build!