[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.

0 files changed, 0 insertions, 0 deletions