Up version number by 1.  This is a 'minor version' update.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@138978 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config
index 76510f0..fffcfaa 100644
--- a/include/__config
+++ b/include/__config
@@ -13,7 +13,7 @@
 
 #pragma GCC system_header
 
-#define _LIBCPP_VERSION 1000
+#define _LIBCPP_VERSION 1001
 
 #define _LIBCPP_ABI_VERSION 1