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

llvm-svn: 131413
diff --git a/libcxx/test/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp b/libcxx/test/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
index f41a70b..e5568ba 100644
--- a/libcxx/test/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
+++ b/libcxx/test/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
@@ -71,6 +71,22 @@
 int G::n_alive = 0;
 bool G::op_run = false;
 
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+class MoveOnly
+{
+    MoveOnly(const MoveOnly&);
+public:
+    MoveOnly() {}
+    MoveOnly(MoveOnly&&) {}
+
+    void operator()(MoveOnly&&)
+    {
+    }
+};
+
+#endif
+
 int main()
 {
     {
@@ -126,5 +142,9 @@
         assert(G::n_alive == 0);
         assert(G::op_run);
     }
+    {
+        std::thread t = std::thread(MoveOnly(), MoveOnly());
+        t.join();
+    }
 #endif  // _LIBCPP_HAS_NO_VARIADICS
 }