[mlir][Transforms] Dialect conversion: Fix bug in `UnresolvedMaterializationRewrite` rollback (#105949)

When an unresolved materialization (`unrealized_conversion_cast` op) is
rolled back, the mapping should be rolled back as well, regardless of
whether it is a source, target or argument materialization. Otherwise,
we accumulate pointers to erased IR in the `mapping`. This is harmless
in most cases, but can cause issues when a new operation is allocated at
the same memory location and the pointer is "reused".

It is not possible to write a test case for this because I cannot
trigger the pointer reuse programmatically.

0 files changed, 0 insertions, 0 deletions