[mlir][memref] Update tests to use memref.assume_alignment properly. (#142358)
With
https://github.com/llvm/llvm-project/commit/ffb9bbfd0745dc22e1fd6edd7b62f72b91f4f6de,
memref.assume_alignment op returns a result value. The revision updates
the tests to reflect the change:
- Update all the lit tests to use the result of memref.assume_alignment,
if it is present.
- Capture the result of the op in lit tests.
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Signed-off-by: hanhanW <hanhan0912@gmail.com>