Brought call_once variadic call up to current spec, which allows move-only functors and move-only arguments, but disallows functors with non-const lvalue reference parameters.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@131414 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed