ClangTidy misc-argument-comment check: don't check arguments to template
parameter packs.

Summary:
This disables this check for std::bind and similar functions that use
parameter packs to forward arguments to a different function. Name of the
parameter pack argument doesn't matter.

Reviewers: klimek

Reviewed By: klimek

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D5168

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@217039 91177308-0d34-0410-b5e6-96231b3b80d8