gh-150587: Guard specialized list-int subscript indices

[KRRT7]

Fixes gh-150587.

This supersedes the earlier closed PR gh-150588. That patch was moved into gh-150425 at the time, but the broad performance PR has not landed, so this keeps the correctness fix as a focused standalone change.

This makes the runtime invariant explicit for the specialized list/int subscript and store-subscript paths. Both opcodes are selected only after seeing a compact non-negative int index, but their runtime guard only ensures an exact int. If the same specialized code later sees a non-compact exact int, it must fall back before calling _PyLong_CompactValue().

Changes:

• Add compact non-negative int fallback checks before _PyLong_CompactValue() in BINARY_OP_SUBSCR_LIST_INT and STORE_SUBSCR_LIST_INT.
• Regenerate the tier-1, tier-2, and _testinternalcapi generated case headers.
• Add regression coverage that warms the specialized opcode with index 0, then calls it with 2**30 + 2 and verifies generic IndexError behavior instead of using the low digit as the list index.

Tests:

• ./python.exe -m test test_opcache -v
• ./python.exe -m test test_opcache -m test_binary_subscr -m test_store_subscr -v
• env PYTHON_JIT=1 ./python.exe -m test test_opcache -m test_binary_subscr -m test_store_subscr -v

[Fidget-Spinner]

LGTM, thanks for catching this bug, just one request.

[Fidget-Spinner]

Why not use EXIT_IF here?