[mlir][arith] Fix `arith.select` canonicalization patterns (#84685) Because `arith.select` does not propagate poison of the second or third operand depending on the condition, some canonicalization patterns are currently incorrect. This patch removes these incorrect patterns, and adds a new pattern to fix the case of `i1` select with constants. Patterns that are removed: * select(predA, select(predB, x, y), y) => select(and(predA, predB), x, y) * select(predA, select(predB, y, x), y) => select(and(predA, not(predB)), x, y) * select(predA, x, select(predB, x, y)) => select(or(predA, predB), x, y) * select(predA, x, select(predB, y, x)) => select(or(predA, not(predB)), x, y) * arith.select %arg, %x, %y : i1 => and(%arg, %x) or and(!%arg, %y) Pattern that is added: * select(pred, false, true) => not(pred) for i1 The first two patterns are incorrect when `predB` is poison and `predA` is false, as a non-poison `y` gets compiled to `poison`. The next two patterns are incorrect when `predB` is poison and `predA` is true, as a non-poison `x` gets compiled to `poison`. The last pattern is incorrect as it propagates poison from all operands afer compilation.
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