[mlir] [llvm] [mlir] Add config for PDL (PR #69927)

[Mehdi Amini via llvm-commits]

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@@ -2333,3 +2334,4 @@ LogicalResult PDLByteCode::rewrite(PatternRewriter &rewriter,
   }
   return result;
 }
+#endif // MLIR_ENABLE_PDL
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joker-eph wrote:

I think we can avoid the macros here by handling this as a library in cmake.

https://github.com/llvm/llvm-project/pull/69927