[Bug c++/51107] [C++11] Accepts invalid literal operator with void argument list.

[3dw4rd at verizon dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51107

--- Comment #3 from Ed Smith-Rowland <3dw4rd at verizon dot net> 2011-11-14 
03:42:45 UTC ---
DECL_USE_TEMPLATE (decl) == 0 for template specializations.
So DECL_TEMPLATE_SPECIALIZATION (current_function_decl) is false.

In fact current_function_decl is null so the second construct must be shielded.