[clang] [MLIR][Presburger] Define matrix inverse for rational matrices (PR #67382)

[Arjun P via cfe-commits]

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@@ -244,6 +244,31 @@ class IntMatrix : public Matrix<MPInt>
 
 };
 
+// An inherited class for rational matrices, with no new data attributes.
+// This is only used for the matrix-related method which apply only
+// to fractions (inverse).
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Superty wrote:

"This class is for functionality that only applies to matrices of fractions."

https://github.com/llvm/llvm-project/pull/67382