llvm-project

d588e49a - [mlir][Transforms][NFC] Dialect conversion: Cache `UnresolvedMaterializationRewrite` (#108359)

[mlir][Transforms][NFC] Dialect conversion: Cache `UnresolvedMaterializationRewrite` (#108359) The dialect conversion maintains a set of unresolved materializations (`UnrealizedConversionCastOp`). Turn that set into a `DenseMap` that maps from ops to `UnresolvedMaterializationRewrite *`. This improves efficiency a bit, because an iteration over `ConversionPatternRewriterImpl::rewrites` can be avoided. Also delete some dead code.