Another vector debug mode test, and a static test on Allocator::value_type. This partially addresses http://llvm.org/bugs/show_bug.cgi?id=15576.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@178064 91177308-0d34-0410-b5e6-96231b3b80d8

include/vector

@@ -502,6 +502,9 @@ public:
     typedef _VSTD::reverse_iterator<iterator>         reverse_iterator;
     typedef _VSTD::reverse_iterator<const_iterator>   const_reverse_iterator;
 
+    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
+                  "Allocator::value_type must be same type as value_type");
+
     _LIBCPP_INLINE_VISIBILITY
     vector()
         _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)