[Bug c++/57673] pack sizeof ... groups ellipsis with preceding expression

[potswa at mac dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57673

--- Comment #1 from David Krauss <potswa at mac dot com> ---
Oops, g::m does not need to be static constexpr to produce an error; the
specifiers should be removed to produce a minimal test.