[llvm] [SelectionDAG] Add initial support for nneg flag on ISD::ZERO_EXTEND. (PR #70872)

[Craig Topper via llvm-commits]

topperc wrote:

> Do we need to add the flag to the zext_in_reg nodes? This question is complicated by the fact that comments in DAGCombine mention such a node, but it doesn't appear to be in the ISDOpcodes.h list.

zext_in_reg is ISD::AND with a trailing ones mask.



https://github.com/llvm/llvm-project/pull/70872