fix bug in alias analysis (#18146)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18146
ghimport-source-id: 4b061c27c5c44ef0d06066490ed16cab3d0c7a64
Stack from [ghstack](https://github.com/ezyang/ghstack):
* **#18146 [jit] fix bug in alias analysis**
We handled hasWriters() incorrectly in the case of wildcards. There's
even a comment describing the correct behavior. Sad!
Much thanks to t-vi for tracking this down and suggesting the fix!
Differential Revision: D14524208
fbshipit-source-id: 8010b54257241bd64013a0d0a8b6e7d22d8c70af
