JDK 11.0.7 is exhibiting the regression from https://bugs.openjdk.org/browse/JDK-8222091.

I think the culprit for the original regression was https://bugs.openjdk.org/browse/JDK-8193462, which was recently backported to JDK 11u. The fix in JDK-8222091 should also be backported.

=== A.java
package p;

import static java.lang.annotation.ElementType.PACKAGE;

import java.lang.annotation.Target;

@Target(PACKAGE)
public @interface A {}
=== package-info.java
@A
package p;
===

The following invocation passes with 11.0.16 and fails with 11.0.17:

$ javadoc package-info.java A.java
...
package-info.java:1: error: unknown tag: A
@A
^