Reland "[ScalarEvolution] createSCEV(): recognize `udiv`/`urem` disguised as an `sdiv`/`srem`"

This reverts commit d3e3f36ff1151f565730977ac4f663a2ccee48ae,
which reverter the original commit 2c16100e6f72075564ea1f67fa5a82c269dafcd3,
but with polly tests now actually passing.

GitOrigin-RevId: a2619a60e4601c445e9ca6e16c76052e00d907ff
2 files changed