unknown enum constant Feature.SEALED_CLASSES

[R H]

Since jdk18+7, I can not build openjdk anymore for amd64 (debian-11 and
centOS 7, both with clang and gcc, plus windows-10). AARCH64 is OK, as
is anything up to jdk18+6.

* For target
buildtools_interim_langtools_modules_java.compiler.interim__the.BUILD_java.compiler.interim_batch:
warning: unknown enum constant Feature.SEALED_CLASSES
warning: unknown enum constant Feature.SEALED_CLASSES
error: warnings found and -Werror specified
1 error
2 warnings

I always use --disable-warnings-as-errors, which seems to be ignored in
this particular instance.

What am I doing wrong?