[21] Top level JDT.Core Issue for Java 21 support

[mpalat]

Umbrella bug for Java 21 activities - Ref https://openjdk.org/projects/jdk/21/ for updates on 21

Please note that until JEP is targeted to 21, list of items for Java 21 release:

• [21] JEP 431: Sequenced Collections #895
• [21] JEP 439: Generational ZGC #1108
• [21] JEP 440: Record Patterns #892
• [21] JEP 441: Pattern Matching for switch #891
• [21] JEP 442: Foreign Function & Memory API (Third Preview) #894
• [21] JEP 444 : Virtual Threads #915
• [21] JEP 446: Scoped Values (Preview) #1113
• [21] JEP 448: Vector API (Sixth Incubator) #1109
• [21] JEP 449: Deprecate the Windows 32-bit x86 Port for Removal #1110
• [21] JEP 451: Prepare to Disallow the Dynamic Loading of Agents #1354
• [21] JEP 452: Key Encapsulation Mechanism API #1355
• [21] JEP 453: Structured Concurrency (Preview) #1114
• [21] Java SE 21 ( JSR 396) Specification #1210

Preview Features from Java Language pov (these are targeted post BETA_JAVA21 milestone):

• [21] JEP 430 String Templates (First Preview) #544
• [21] JEP 443: Unnamed Patterns and Variables (Preview) #893
• [21] JEP 445: Unnamed Classes and Instance Main Methods (Preview) #1106

Release Activities captured in : #1380

[mpalat]

BETA_JAVA21 branch for Java 21 development has been created. @noopur2507 @jarthana please note.

[mpalat]

Happy to note that Java 21 support released as planned above -
ref the release mail for https://www.eclipse.org/lists/eclipse-dev/msg12203.html