This PR adds annotation support to `tirx.Call` so downstream codegen
users can attach call-level metadata and preserve it through TIRX
transforms.
What changed:
- Add `CallNode::annotations` and expose it through reflection.
- Add Python `tvm.tirx.Call(..., annotations=...)` support.
- Preserve call annotations in C++ and Python expression mutators.
- Preserve annotations across TIRX/arith passes that rebuild equivalent
calls.
- Print annotated calls as `Tx.Call(..., annotations={...})` and support
script roundtrip.
- Add regression coverage for annotated calls, mutator preservation,
script roundtrip, and simplify preservation.
This pr also cleans some stuff that #19596 didn't clean completely
Shushi Hong
cae6cb89b7