[C++ Patch] PR 35147 and 37737

[Paolo Carlini]

Hi,
> Why is the NUM_TMPL_ARGS check required?  (Normally, we want to handle
> f<> just like f<int>; it just happens that the set of arguments is  
> empty.)

Yes, the problem is exactly that we use the same representation, a  
TREE_VEC, but with zero elements in that case, that crashes  
get_innermost_template_args, when checking is enabled, at least.

Paolo.