[Mlir-commits] [mlir] [mlir][Transforms] Fix build after #116524 (part 2) (PR #121662)

[Matthias Springer]

matthias-springer wrote:

This is how I noticed that something was wrong:
```c++
  for (auto it : rewriterImpl.mapping.mapping) {
    const auto &s = it.second;
    const auto &f = it.first;
    llvm::errs() << "A : " << rewriterImpl.mapping.mapping.contains(s) << "\n";
    llvm::errs() << "B : " << rewriterImpl.mapping.mapping.contains(f) << "\n";
  }
```

Without this PR, the above code sometimes prints:
```
A : 0
B : 0
```


https://github.com/llvm/llvm-project/pull/121662