Use pop_back_val() instead of both back() and pop_back().
No functionality change intended.

llvm-svn: 189112
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 6ebfb57..53b8668 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -1249,8 +1249,7 @@
     if (Queue.empty())
       return false;
 
-    Current = Queue.back();
-    Queue.pop_back();
+    Current = Queue.pop_back_val();
   }
 
   return false;