8248843: java in source-file mode suggests javac-only options

Reviewed-by: vromero

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

@@ -348,6 +348,7 @@ public class Main {
 
         // add implicit options
         javacOpts.add("-proc:none");
+        javacOpts.add("-Xdiags:verbose");
 
         return javacOpts;
     }