fix arena struct

Author: cocolato

Include/internal/pycore_optimizer.h

@@ -37,6 +37,9 @@ typedef struct _JitOptContext {
     // Arena for the symbolic types.
     ty_arena t_arena;
 
+    // Arena for the slots mappings.
+    slots_arena s_arena;
+
     JitOptRef *n_consumed;
     JitOptRef *limit;
     JitOptRef locals_and_stack[MAX_ABSTRACT_INTERP_SIZE];