Visual Studio integration: procedure with IMPURE attribute missing from members drop-down list

In case this is not a known issue: consider the code shown below: procedure with IMPURE attribute doesn't show up in the members drop-down list in Visual Studio.  Also, this particular keyword doesn't receive the syntax highlighting either.

module m

contains

   subroutine foo()

   end subroutine foo

   pure subroutine bar()

   end subroutine bar

   elemental subroutine foobar()

   end subroutine foobar

   impure elemental subroutine snafu()

   end subroutine snafu

end module m