gh-151830: Raise ValueError instead of SystemError for invalid code objects in marshal.loads()

[tonghuaroot]

marshal.loads() already raises ValueError with a "bad marshal data (...)" message for malformed input, but a code object whose internal fields
are inconsistent (for example a localsplusnames tuple whose length differs
from the localspluskinds bytes) makes _PyCode_Validate() call
PyErr_BadInternalCall(), which surfaces as
SystemError: bad argument to internal function. This converts that one
case to ValueError: bad marshal data (invalid code object), so the
code-object path is consistent with marshal's existing bad-marshal-data
errors. The change is narrowly scoped to the SystemError from
PyErr_BadInternalCall() and leaves the other _PyCode_Validate() failures
(which already raise ValueError/OverflowError) unchanged.

A regression test was added to Lib/test/test_marshal.py and a NEWS entry
was added under Misc/NEWS.d/.

• Issue: marshal.loads() raises SystemError instead of ValueError on an invalid code object #151830

[sobolevn]

(not a full review, just several comments about the test)

[sobolevn]

Can this actually happen? If not, please use self.assertEqual(kinds, ...)

[tonghuaroot]

Done — replaced the self.fail with assertEqual(kinds, ...), using a no-arg function so the locals are all plain CO_FAST_LOCAL and the expected kinds is deterministic.

[sobolevn]

Suggested change

	with self.assertRaises(ValueError):
	with self.assertRaisesRegex(ValueError, 'bad marshal data, \(invalid code object\)'):

[tonghuaroot]

Applied. I dropped the comma so the pattern matches the actual message — the existing bad marshal data (...) convention in marshal.c.