8247382: doclint errors (missing comments) in jdk.compiler and jdk.javadoc

Reviewed-by: darcy

src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java

@@ -38,6 +38,8 @@ public class Main {
     /** Main entry point for the launcher.
      *  Note: This method calls System.exit.
      *  @param args command line arguments
+     *  @throws Exception only if an uncaught internal exception occurs;
+     *      just retained for historical compatibility
      */
     public static void main(String[] args) throws Exception {
         System.exit(compile(args));

src/jdk.javadoc/share/classes/jdk/javadoc/doclet/DocletEnvironment.java

@@ -138,6 +138,9 @@ public interface DocletEnvironment {
      */
     Kind getFileKind(TypeElement type);
 
+    /**
+     * The mode specifying the level of detail of module documentation.
+     */
     enum ModuleMode {
         /** Indicate API level documentation is required */
         API,

src/jdk.javadoc/share/classes/jdk/javadoc/doclet/StandardDoclet.java

@@ -70,6 +70,10 @@ public class StandardDoclet implements Doclet {
 
     private final HtmlDoclet htmlDoclet;
 
+    /**
+     * Creates an instance of the standard doclet, used to generate HTML-formatted
+     * documentation.
+     */
     public StandardDoclet() {
         htmlDoclet = new HtmlDoclet(this);
     }