[JIT] Fix a bug of rejecting ops with AliasAnalysisKind::CONSERVATIVE (#64336)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64336

Currently AliasDB rejects any user-defined ops with `AliasAnalysisKind::CONSERVATIVE` if they do not have a special treatment for alias analysis. For example, the following alias schema gets rejects:

```
  m.def(torch::schema(
      "namescope::my_op(...) -> ...",
      c10::AliasAnalysisKind::CONSERVATIVE));
```

This rejection condition is contradictory: AliasDB can handle ops with `CONSERVATIVE` in a general way without any special casing at https://fburl.com/diffusion/op5u72sk calling https://fburl.com/diffusion/h3aws5dd which seems very appropriate to be conservative for alias analysis.

This change corrects the rejection condition to be satisfied for ops *with* special casing but have `CONSERVATIVE`, since they both cannot be used simultaneously.

Test Plan:
Confirmed that
```
  m.def(torch::schema(
      "namescope::my_op(...) -> ...",
      c10::AliasAnalysisKind::CONSERVATIVE));
```
gets accepted and `my_op`'s all inputs and outputs are put to point to wildcard(*) by AliasDB.

Reviewed By: eellison

Differential Revision: D30690121

fbshipit-source-id: 431cc1a84edd5227f52b44a0fd85d5eb16f3c288
diff --git a/torch/csrc/jit/runtime/operator.cpp b/torch/csrc/jit/runtime/operator.cpp
index 6508016..c1265a6 100644
--- a/torch/csrc/jit/runtime/operator.cpp
+++ b/torch/csrc/jit/runtime/operator.cpp
@@ -353,10 +353,10 @@
           op.schema().name(),
           ". File a bug to add a case for this operator.\n");
     }
-    if (!aliasAnalysisHasSpecialCaseFor(s) &&
+    if (aliasAnalysisHasSpecialCaseFor(s) &&
         op.aliasAnalysisKind() == AliasAnalysisKind::CONSERVATIVE) {
       AT_ERROR(
-          "Missing special case in alias analysis for non-schematized"
+          "Conflict in special casing in alias analysis for non-schematized"
           " operator ",
           op.schema().name(),
           ". File a bug to add a case for this operator.\n");