bpo-43908: Make heap types converted during 3.10 alpha immutable (GH-26351) (GH-26766)

* Make functools types immutable

* Multibyte codec types are now immutable

* pyexpat.xmlparser is now immutable

* array.arrayiterator is now immutable

* _thread types are now immutable

* _csv types are now immutable

* _queue.SimpleQueue is now immutable

* mmap.mmap is now immutable

* unicodedata.UCD is now immutable

* sqlite3 types are now immutable

* _lsprof.Profiler is now immutable

* _overlapped.Overlapped is now immutable

* _operator types are now immutable

* winapi__overlapped.Overlapped is now immutable

* _lzma types are now immutable

* _bz2 types are now immutable

* _dbm.dbm and _gdbm.gdbm are now immutable
(cherry picked from commit 00710e6346fd2394aa020b2dfae170093effac98)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>
diff --git a/Modules/_operator.c b/Modules/_operator.c
index 5bd5a3b..d5e092e 100644
--- a/Modules/_operator.c
+++ b/Modules/_operator.c
@@ -1133,7 +1133,8 @@ static PyType_Spec itemgetter_type_spec = {
     .name = "operator.itemgetter",
     .basicsize = sizeof(itemgetterobject),
     .itemsize = 0,
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+              Py_TPFLAGS_IMMUTABLETYPE),
     .slots = itemgetter_type_slots,
 };
 
@@ -1464,7 +1465,8 @@ static PyType_Spec attrgetter_type_spec = {
     .name = "operator.attrgetter",
     .basicsize = sizeof(attrgetterobject),
     .itemsize = 0,
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+              Py_TPFLAGS_IMMUTABLETYPE),
     .slots = attrgetter_type_slots,
 };
 
@@ -1719,7 +1721,8 @@ static PyType_Spec methodcaller_type_spec = {
     .name = "operator.methodcaller",
     .basicsize = sizeof(methodcallerobject),
     .itemsize = 0,
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+              Py_TPFLAGS_IMMUTABLETYPE),
     .slots = methodcaller_type_slots,
 };