This PR fixes two independent test-isolation issues that only surface
when certain test files run together in one pytest session.
1. Fix `_DialectRedirectFinder` duplicate module execution
`_DialectRedirectFinder.find_spec` used to pre-register the redirect
target module under the legacy alias name before returning the alias
spec.
This interacts badly with CPython import logic: when the requested
module name is already in `sys.modules`, CPython may ignore the returned
alias spec and reuse the target module's original spec instead. As a
result, the target source can be executed again under the canonical
module name, creating a duplicate module object.
This caused patches on aliased modules to silently miss the module
object used by existing code. For example,
`unittest.mock.patch("tvm.tirx.script.builder.buffer_store")` patched
the duplicate module, while the tirx parser still held references to the
original one, so `test_scalar_assign_error_not_swallowed` failed with
`DID NOT RAISE`.
This pr removes the pre-registration and let the import machinery
register the alias normally. Since the alias spec is now used,
`_AliasLoader.exec_module` also restores the canonical `__spec__` and
`__loader__` to avoid stale alias metadata on the loaded module.
2. Remove unused `tirx.intrin_test` op registration
`test_s_tir_transform_lower_match_buffer.py` registered a dummy op:
```python
tvm.ir.register_op_attr("tirx.intrin_test", "")
```
This was a leftover from the old TVMScript parser and is no longer
needed. The modern tirx parser eagerly evaluates `intrin_test(...)`
calls into `T.evaluate(0)`, so this op never appears in parsed IR.
The only remaining effect was adding a category-less `tirx.intrin_test`
entry to the global op registry, which could break
`test_registered_tirx_ops_have_exactly_one_category` depending on test
import order.
This pr removes the unused registration.
Shushi Hong
07e60343bc