xo-arena: annex ArenaConfig.*pp from xo-alloc2/

src/alloc2/ArenaConfig.cpp

@@ -1,17 +0,0 @@
-/** @file ArenaConfig.cpp
- *
- *  @author Roland Conybeare, Dec 2025
- **/
-
-#include "ArenaConfig.hpp"
-namespace xo {
-    namespace mm {
-        ArenaConfig
-        ArenaConfig::simple(std::size_t z)
-        {
-            return ArenaConfig { .name_ = "anonymous", .size_ = z };
-        }
-    }
-}
-
-/* end ArenaConfig.cpp */

src/alloc2/CMakeLists.txt

@@ -8,7 +8,7 @@ set(SELF_SRCS
     cmpresult.cpp
 
     AAllocator.cpp
-    ArenaConfig.cpp
+#    ArenaConfig.cpp
     DArena.cpp
     IAllocator_Any.cpp
     IAllocator_DArena.cpp