[mlir][IR] Fix bug in AffineExpr simplifier `lhs % rhs` where `lhs = lhs floordiv rhs` (#119245)

Fixes an issue where the `SimpleAffineExprFlattener` would simplify
`lhs % rhs` to just `-(lhs floordiv rhs)` instead of 
`lhs - (lhs floordiv rhs)`
if `lhs` happened to be equal to `lhs floordiv rhs`.

The reported failure case was 
`(d0, d1) -> (((d1 - (d1 + 2)) floordiv 8) % 8)`
from https://github.com/llvm/llvm-project/issues/114654.

Note that many paths that simplify AffineMaps (e.g. the AffineApplyOp
folder and canonicalization) would not observe this bug because of
of slightly different paths taken by the code. Slightly different
grouping of the terms could also result in avoiding the bug.

Resolves https://github.com/llvm/llvm-project/issues/114654.

0 files changed, 0 insertions, 0 deletions