pythongh-102674: Remove _specialization_stats from Lib/opcode.py (python#102685)

It's not use except in a test, so move it there instead.

Author: corona10

Lib/opcode.py

@@ -389,14 +389,6 @@ def pseudo_op(name, op, real_ops):
 _specialized_instructions = [
     opcode for family in _specializations.values() for opcode in family
 ]
-_specialization_stats = [
-    "success",
-    "failure",
-    "hit",
-    "deferred",
-    "miss",
-    "deopt",
-]
 
 _cache_format = {
     "LOAD_GLOBAL": {

Lib/test/test__opcode.py

@@ -69,8 +69,7 @@ def test_stack_effect_jump(self):
 
 class SpecializationStatsTests(unittest.TestCase):
     def test_specialization_stats(self):
-        stat_names = opcode._specialization_stats
-
+        stat_names = ["success", "failure", "hit", "deferred", "miss", "deopt"]
         specialized_opcodes = [
             op.lower()
             for op in opcode._specializations