Introduce the allocator stuff again

core_compiler_interface.hpp

@@ -13,6 +13,15 @@ struct Ast_Expr;
 
 #ifndef CORE_BASE
 #define CORE_BASE
+
+struct Allocator {
+  typedef void *Allocate(Allocator *, size_t);
+  typedef void  Deallocate(Allocator *, void *p);
+
+  Allocate *allocate;
+  Deallocate *deallocate;
+};
+
 struct String{
   uint8_t *str;
   int64_t len;