[CVP] @llvm.[us]{min,max}() intrinsics handling
If we can tell that either one of the arguments is taken,
bypass the intrinsic.
Notably, we are indeed fine with non-strict predicate:
* UL: https://alive2.llvm.org/ce/z/69qVW9 https://alive2.llvm.org/ce/z/kNFTKf
https://alive2.llvm.org/ce/z/AvaPw2 https://alive2.llvm.org/ce/z/oxo53i
* UG: https://alive2.llvm.org/ce/z/wxHeGH https://alive2.llvm.org/ce/z/Lf76qx
* SL: https://alive2.llvm.org/ce/z/hkeTGS https://alive2.llvm.org/ce/z/eR_b-W
* SG: https://alive2.llvm.org/ce/z/wEqRm7 https://alive2.llvm.org/ce/z/FpAsVr
Much like with all other comparison handling in CVP,
while we could sort-of handle two Value's,
at least for plain ICmpInst it does not appear to be worthwhile.
This only fires 78 times on test-suite + dt + rs,
but we don't canonicalize to these yet. (only SCEV produces them)