Align Python 3.15 bytecode tooling (#9344)

Extract independent bytecode tooling from the Python 3.15 integration. Decode packed import-name arguments without changing older-interpreter fallback behavior, validate canonical opcode numbering, bound deoptimization families to the enum, and reuse parsed CPython analysis.

Validated generators reproduce tracked metadata exactly; normal, lazy and eager import fallback matches canonical disassembly. No interpreter, generated metadata or test changes.

Assisted-by: OpenAI Codex: model version unavailable

scripts/dis_dump.py

@@ -170,12 +170,22 @@ def _resolve_arg_fallback(code, opname, arg):
             "LOAD_ATTR",
             "STORE_ATTR",
             "DELETE_ATTR",
-            "IMPORT_NAME",
             "IMPORT_FROM",
             "LOAD_FROM_DICT_OR_GLOBALS",
         ):
             if 0 <= arg < len(code.co_names):
                 return code.co_names[arg]
+        elif opname == "IMPORT_NAME":
+            name_idx, policy = arg, 0
+            if sys.version_info >= (3, 15):
+                name_idx, policy = arg >> 2, arg & 3
+            if 0 <= name_idx < len(code.co_names):
+                name = code.co_names[name_idx]
+                if policy & 1 and name:
+                    return f"{name} + lazy"
+                if policy & 2 and name:
+                    return f"{name} + eager"
+                return name
         elif opname == "LOAD_SUPER_ATTR":
             name_idx = arg >> 2
             if 0 <= name_idx < len(code.co_names):

tools/opcode_metadata/cpython.py

@@ -1,3 +1,4 @@
+import functools
 import os
 import pathlib
 import sys
@@ -18,6 +19,7 @@ from analyzer import SKIP_PROPERTIES, Analysis, Family, Properties, analyze_file
 from stack import get_stack_effect
 
 
+@functools.cache
 def get_analysis() -> Analysis:
     from generators_common import DEFAULT_INPUT
 

tools/opcode_metadata/opcodes.py

@@ -33,10 +33,11 @@ class OpcodeInfo:
 
             for member in family.members:
                 member_name = to_pascal_case(member.name)
-                if member.name == family_name:
+                if member_name == family_name or member_name not in names:
                     continue
 
-                res[family_name].append(member_name)
+                if member_name not in res[family_name]:
+                    res[family_name].append(member_name)
 
         return dict(res)
 
@@ -76,6 +77,17 @@ def iter_opcodes(text: str, override_confs: OverrideConfs) -> Iterable[Opcode]:
         opcode = Opcode.from_str(entry)
 
         rust_name = opcode.rust_name
+        # Shared opcodes use CPython's wire-format IDs; RustPython-only
+        # instructions must occupy an otherwise unused slot.
+        expected_id = analysis.opmap.get(opcode.cpython_name)
+        if expected_id is not None and opcode.id != expected_id:
+            raise ValueError(
+                f"{rust_name} has opcode ID {opcode.id}; CPython requires {expected_id}"
+            )
+        if expected_id is None and opcode.id in analysis.opmap.values():
+            raise ValueError(
+                f"RustPython-only opcode {rust_name} collides with CPython ID {opcode.id}"
+            )
         override = override_confs.get(rust_name, SKIP_OVERRIDE)
 
         cpython_name = opcode.cpython_name