[libc++] Include language.h inside __config (#114269)

ldionne · web-flow · commit 61498a897dd3 · 2024-10-31T11:35:30.000-04:00
We were getting this include transitively via availability.h, but we
really should be including it explicitly.
diff --git a/libcxx/include/__config b/libcxx/include/__config
@@ -14,6 +14,7 @@
 #include <__configuration/abi.h>
 #include <__configuration/availability.h>
 #include <__configuration/compiler.h>
+#include <__configuration/language.h>
 #include <__configuration/platform.h>
 
 #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
