Fix Javadoc on Java 11+.

pom.xml

@@ -608,6 +608,7 @@
 
     <commons.jacoco.version>0.8.3</commons.jacoco.version>
     <commons.surefire.version>3.0.0-M3</commons.surefire.version>
+    <commons.javadoc.version>3.1.0</commons.javadoc.version>
 
     <!-- generate report even if there are binary incompatible changes -->
     <commons.japicmp.breakBuildOnBinaryIncompatibleModifications>false</commons.japicmp.breakBuildOnBinaryIncompatibleModifications>
@@ -653,8 +654,8 @@
     <plugins>
       <plugin>
         <artifactId>maven-javadoc-plugin</artifactId>
-        <version>${commons.javadoc.version}</version>
         <configuration>
+          <source>${maven.compiler.source}</source>
           <quiet>true</quiet>
           <encoding>utf-8</encoding>
           <docEncoding>utf-8</docEncoding>
@@ -904,19 +905,6 @@
       </properties>
     </profile>
 
-    <profile>
-      <id>java11+</id>
-      <activation>
-        <jdk>[11,)</jdk>
-      </activation>
-      <properties>
-        <!-- workaround for https://bugs.openjdk.java.net/browse/JDK-8212233
-             which causes javadoc to fail with "Exit code: 1 - javadoc: error - The code being documented uses modules
-             but the packages defined in https://docs.oracle.com/javase/7/docs/api/ are in the unnamed module."  -->
-        <maven.javadoc.skip>true</maven.javadoc.skip>
-      </properties>
-    </profile>
-
     <profile>
       <id>benchmark</id>
       <properties>