gh-110190: Fix ctypes structs with array on SPARC

Author: kulikjak

Modules/_ctypes/stgdict.c

@@ -606,7 +606,7 @@ PyCStructUnionType_update_stginfo(PyObject *type, PyObject *fields, int isStruct
 /*
  * The value of MAX_STRUCT_SIZE depends on the platform Python is running on.
  */
-#if defined(__aarch64__) || defined(__arm__) || defined(_M_ARM64)
+#if defined(__aarch64__) || defined(__arm__) || defined(_M_ARM64) || defined(__sparc__)
 #  define MAX_STRUCT_SIZE 32
 #elif defined(__powerpc64__)
 #  define MAX_STRUCT_SIZE 64