[InstCombine] Regard zext nneg as sext when folding add(zext neg(add)) (#88887)

fixes #88348
proof:
https://alive2.llvm.org/ce/z/fJnM7t
test will be added later

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Signed-off-by: ZelinMa557 <3388706467@qq.com>
GitOrigin-RevId: 97c71247312c7e5261168283c13cd7e3ecd039a5
2 files changed