[patch c++]: Fix PR/64100 'A static assert using the the current class in a noexcept test leads to a segfault'

[Jason Merrill]

On 12/04/2014 10:57 AM, Kai Tietz wrote:
> Well, I spared that as this is an invalid code bug with a lot of
> side-errors, which might change over time.

Every patch should have an associated testcase unless it's fixing an 
existing test or writing a testcase is somehow not feasible.  Many tests 
in the testsuite deal with invalid code bugs.  :)

Jason