cp_maybe_constrained_type_specifier asserted that the decl passed in 
would be of type OVERLOAD, however a clean build of the compiler was 
broken since it could also be a BASELINK.  I'm not entirely sure when 
this is the case, except that it seems to happen with class member 
templates as it also caused a test case in my next patch to fail.  The 
solution is to check for a BASELINK and extract the functions from it.

The possibility of decl being a BASELINK is asserted near the call in 
cp_parser_template_id (cp_maybe_partial_concept_id just calls the 
function in question at this time).

2014-06-17  Braden Obrzut  <admin@maniacsvault.net>
     * gcc/cp/parser.c (cp_maybe_constrained_type_specifier): Fix assertion
     failure if baselink was passed in as decl.