On the API level, this likely means just adding ClassInfo.isValue() (or isValueClass()). However, this also involves changing the serialization format.
Per https://openjdk.org/jeps/401:
Whether a class is an identity class or a value class is recorded in its class file. Identity classes have the ACC_IDENTITY flag set; value classes do not. This flag supersedes the legacy ACC_SUPER flag. The JVM Specification always recommended that compilers and tools set the ACC_SUPER flag in class files, so by default, compilers and tools can continue to set the flag in new class files and generate identity classes.
On the API level, this likely means just adding
ClassInfo.isValue()(orisValueClass()). However, this also involves changing the serialization format.Per https://openjdk.org/jeps/401: