Marshall Clow's fix for Bug 8421.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@122825 91177308-0d34-0410-b5e6-96231b3b80d8

CREDITS.TXT

@@ -12,4 +12,7 @@ N: Howard Hinnant
 E: hhinnant@apple.com
 D: Architect and primary author of libc++
 
-
+N: Marshall Clow
+E: marshall@idio.com
+E: mclow@qualcomm.com
+D: Minor patches and bug fixes.

include/map

@@ -350,7 +350,7 @@ template <class _Key, class _Tp, class _Compare, bool = is_empty<_Compare>::valu
 class __map_value_compare
     : private _Compare
 {
-    typedef pair<_Key, _Tp> _P;
+    typedef pair<typename std::remove_const<_Key>::type, _Tp> _P;
     typedef pair<const _Key, _Tp> _CP;
 public:
     _LIBCPP_INLINE_VISIBILITY
@@ -393,7 +393,7 @@ class __map_value_compare<_Key, _Tp, _Compare, false>
 {
     _Compare comp;
 
-    typedef pair<_Key, _Tp> _P;
+    typedef pair<typename std::remove_const<_Key>::type, _Tp> _P;
     typedef pair<const _Key, _Tp> _CP;
 
 public: