[llvm] [AssumptionCache] Fix removeAffectedValues() when value is repeated in AssumeInst (PR #205275)

[Nikolas Klauser via llvm-commits]

================
@@ -129,15 +146,28 @@ void AssumptionCache::removeAffectedValues(AssumeInst *CI) {
       if (Elem.Assume == CI) {
         Found = true;
         Elem.Assume = nullptr;
+
+        ExpectedMatches[AV.Assume]--;
+        assert(ExpectedMatches[AV.Assume] >= 0);
+        // After ExpectedMatches[AV.Assume] == 0, we still need to iterate
+        // through this loop to determine the value of HasNonnull, to avoid
+        // prematurely calling AffectedValues.erase(AVI).
       }
       HasNonnull |= !!Elem.Assume;
       if (HasNonnull && Found)
         break;
     }
-    assert(Found && "already unregistered or incorrect cache state");
+
+    if (ExpectedMatches[AV.Assume] > 0)
+      assert(Found && "already unregistered or incorrect cache state");
+
     if (!HasNonnull)
       AffectedValues.erase(AVI);
   }
+
+  for (auto &AV : Affected)
+    assert(!ExpectedMatches[AV.Assume] &&
+           "already unregistered or incorrect cache state");
----------------
philnik777 wrote:

```suggestion
  assert(none_of(Affected, [&](auto& AV) { return ExpectedMatches[AV.Assume]; }) &&
           "already unregistered or incorrect cache state");
```

https://github.com/llvm/llvm-project/pull/205275