8271159: [REDO] JDK-8249634 doclint should report implicit constructor as missing javadoc comments

Reviewed-by: darcy

test/langtools/tools/doclint/SummaryTest.java

@@ -16,4 +16,7 @@ public class SummaryTest {
 
     /** {@summary legal} text {@summary illegal} **/
     public void m2() {}
+
+    /** . */
+    private SummaryTest() { }
 }