Add sanity check in lb_create_procedure

src/llvm_backend.cpp

@@ -2741,6 +2741,9 @@ void lb_ensure_abi_function_type(lbModule *m, lbProcedure *p) {
 lbProcedure *lb_create_procedure(lbModule *m, Entity *entity, bool ignore_body) {
 	GB_ASSERT(entity != nullptr);
 	GB_ASSERT(entity->kind == Entity_Procedure);
+	if (!entity->Procedure.is_foreign) {
+		GB_ASSERT(entity->flags |= EntityFlag_ProcBodyChecked);
+	}
 
 	String link_name = {};