8002146: javadoc doesn't release resources in a timely manner

Reviewed-by: darcy

src/share/classes/com/sun/tools/javadoc/JavadocMemberEnter.java

@@ -81,6 +81,9 @@ public class JavadocMemberEnter extends MemberEnter {
             docenv.makeAnnotationTypeElementDoc(meth, docComment, tree, lineMap);
         else
             docenv.makeMethodDoc(meth, docComment, tree, lineMap);
+
+        // release resources
+        tree.body = null;
     }
 
     @Override

src/share/classes/com/sun/tools/javadoc/Start.java

@@ -394,6 +394,9 @@ class Start {
                 // legacy?
                 languageVersion == null || languageVersion == LanguageVersion.JAVA_1_1, quiet);
 
+        // release resources
+        comp = null;
+
         // pass off control to the doclet
         boolean ok = root != null;
         if (ok) ok = docletInvoker.start(root);