[X86] Add a DAG combine for (i32 (sext (i8 (x86isd::setcc_carry)))) -> (i32 (x86isd::setcc_carry)) and remove isel patterns.
Same for any_extend though we don't have coverage for that.
The test changes are because isel didn't check one use of the
setcc_carry. So in isel we would end up with two different
sized setcc_carry instructions. And since it clobbers
the flags we would need to recreate the flags for the second
This code handles additional uses by truncating the new wide
setcc_carry back to the original size for those uses.