Add origin of changes within contents

Author: cferry-AMD

mlir/include/mlir/Dialect/Affine/IR/AffineTraits.td

@@ -17,6 +17,9 @@ include "mlir/IR/OpBase.td"
 // Trait to declare that an op result is an affine dimension identifier.
 // Prevents the result from being seen as a symbol into AffineMaps
 // and IntegerSets.
+// This is a deviation from upstream to consider linalg.index as
+// a dimension rather than a symbol. See this PR:
+// https://github.com/Xilinx/llvm-project/pull/537
 def AffineDim : NativeOpTrait<"AffineDim">;
 
 #endif // AFFINE_TRAITS

mlir/test/Dialect/Linalg/affine-if.mlir

@@ -2,6 +2,9 @@
 
 // Check that linalg.index does not cause folding of affine.if set to
 // a symbolic set.
+// This is a deviation from upstream MLIR.
+// The origin of this test is that PR:
+// https://github.com/Xilinx/llvm-project/pull/537
 
 // CHECK: = affine_set<(d0) : (-d0 + 5 >= 0)>
 #set = affine_set<(d0) : (-d0 + 5 >= 0)>