re PR c++/2513 (internal template template parameter causes ICE)
PR c++/2513
* decl.c (make_typename_type): Use dependent_type_p.
(make_unbound_class_template): Likewise.
* pt.c (instantiate_class_template): Increment
processing_template_decl during substitution of template friend
function. Preincrement processing_template_decl rather than
postincrement.
(get_mostly_instantiated_function_type): Increment
processing_template_decl during partial substitution of function
type.