provided by an outer template.
We made the incorrect assumption in various places that the only way we
can have any arguments already provided for a pack during template
argument deduction was from a partially-specified pack. That's not true;
we can also have arguments from an enclosing already-instantiated
template, and that can even result in the function template's own pack
parameters having a fixed length and not being packs for the purposes of
template argument deduction.
llvm-svn: 337481
results in a template having too many arguments, but all the trailing arguments
are packs, that's OK if we have a partial pack substitution: the trailing pack
expansions may end up empty.
llvm-svn: 210350
Richard Smith