Update JVMTI ForceEarlyReturnVoid, and the equivalent JDWP command and JDI method, to specify that the operation fails if the target thread's top frame is a constructor or the class initializer of a class with strictly-initialized fields.
Several options have been explored for both constructors and class initializers, the details are attached to the JBS issue. The changes are very simple. ClassFileParser::parse_fields records if the class has class has strict instance fields, as it does already for strict static fields. JvmtiEnvBase::check_top_frame is changed to check if the top frame is a constructor of a class with strict instance fields in the class hierarchy or the initializer of a class with strict static fields. This replaces the check if the top frame is a value class constructor, the interim solution for the initial JEP 539 integration. In jvmti.xml, the custom XML element `externallink` is updated to support the `sup` element so a "PREVIEW" superscript can decorate links to preview APIs. Test ForceEarlyReturnStrictInitFields is added to test ForceEarlyReturnVoid when the target thread's top frame is the constructor, method, or class initializer of a a class with strictly-initialized fields. Testing: tier 1-5 --------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - Fix typos in comments/docs - Merge branch 'master' into JDK-8387648 - API doc improvements - Update - Merge branch 'master' into JDK-8387648 - Merge branch 'master' into JDK-8387648 - Move has_strict_instance_fields_in_hierarchy implementation out of header file - Merge branch 'master' into JDK-8387648 - Merge branch 'master' into JDK-8387648 - Reorder to explain constructors first, add API note - ... and 2 more: https://git.openjdk.org/jdk/compare/0b44562c...24781212 Changes: https://git.openjdk.org/jdk/pull/32198/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=32198&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8387648 Stats: 1148 lines in 14 files changed: 802 ins; 316 del; 30 mod Patch: https://git.openjdk.org/jdk/pull/32198.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/32198/head:pull/32198 PR: https://git.openjdk.org/jdk/pull/32198
