[InstCombine] allow more min/max with 'not' folds for intrinsics

isFreeToInvert allows min/max with 'not' on both operands,
so easing the argument restriction catches the case where
that operand has one use.

We already handle the sub-patterns when there are less uses:
https://alive2.llvm.org/ce/z/8Jatm_

...but this is another step towards parity with the
equivalent icmp+select idioms ( D98152 ).

Differential Revision: https://reviews.llvm.org/D109059