66580f77b8
`unresolvedMaterializations` is a mapping from `UnrealizedConversionCastOp` to `UnresolvedMaterializationRewrite`. This mapping is needed to find the correct type converter for an unresolved materialization. With this commit, `unresolvedMaterializations` is updated immediately when an op is being erased. This also cleans up the code base a bit: `SingleEraseRewriter` is now used only during the "cleanup" phase and no longer needed as a field of `ConversionRewriterImpl`. This commit is in preparation of the One-Shot Dialect Conversion refactoring: `allowPatternRollback = false` will in the future trigger immediate materialization of all IR changes.
Multi-Level Intermediate Representation
See https://mlir.llvm.org/ for more information.