Exclude frame-wide StopIteration cleanup from exception chains

[EiNSTeiN-]

I am opening this PR to keep a generator's frame-wide cleanup from swallowing later statements into an earlier exception handler. The code below currently decompiles with an extra else that changes which values are yielded after a handled exception:

def select(work):
    try:
        yield work("first")
    except ValueError:
        yield 2
    yield 3
    try:
        yield work("last")
    except KeyError:
        yield 5
    yield 6

Two sequential exception scopes must resume their shared mainline in order. The exception-chain extent walker can follow the generator/coroutine's frame-wide StopIteration conversion handler and absorb later mainline statements into an earlier lexical handler. In this example, yield 3 and the second try are moved into an else belonging to the first try, so they are skipped when ValueError is handled.

The change makes chain_extent ignore exception-table targets whose head is CALL_INTRINSIC_1 3. This target is frame cleanup, not a source-level except or finally continuation. The same correction applies to the asynchronous-generator variation, written as async def select(work) with the same body.

The relevant CALL_INTRINSIC_1 operation, including INTRINSIC_STOPITERATION_ERROR, is introduced in Python 3.12.