Reviewed-by: chegar

Summary: Fix corner cases involving MethodHandles.permuteArguments with long or double argument lists.
Reviewed-by: twisti, never

Summary: Update <jdkroot>/README.html with correct mention of Java DB, add JDK specific README files to <jdkroot>/db and <jdkroot>/demo/db.
Reviewed-by: ohair

Reviewed-by: valeriep, asaha, alanb

Reviewed-by: chegar, alanb