Also change the member enumerator value into a member constant "static const
int value", since deprecation of the class does not work in many cases, and
any attempt to deprecate an enumerator will make the compiler barf.

In addition, deprecate the default constructor.  That should catch most cases
on recent compilers.

Derive from integral_constant<int,...> so classes using this to implement a
replacement for the forbidden partial specializations of functions don't have
to provide compatibility declarations during the migration.

[[Imported from SVN: r6274]]