Implement full support for non-pointer pointers in custom allocators for vector.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@185093 91177308-0d34-0410-b5e6-96231b3b80d8

test/containers/sequences/vector/db_iterators_5.pass.cpp

@@ -21,8 +21,11 @@
 #include <exception>
 #include <cstdlib>
 
+#include "../../min_allocator.h"
+
 int main()
 {
+    {
     typedef int T;
     typedef std::vector<T> C;
     C c(1);
@@ -32,6 +35,20 @@ int main()
     i = c.begin();
     i += 2;
     assert(false);
+    }
+#if __cplusplus >= 201103L
+    {
+    typedef int T;
+    typedef std::vector<T, min_allocator<T>> C;
+    C c(1);
+    C::iterator i = c.begin();
+    i += 1;
+    assert(i == c.end());
+    i = c.begin();
+    i += 2;
+    assert(false);
+    }
+#endif
 }
 
 #else