[llvm] [clang] [Instcombine] use zext's nneg flag for icmp folding (PR #70845)

[Nikita Popov via llvm-commits]

================
@@ -0,0 +1,145 @@
+; RUN: opt < %s --O3 -S | FileCheck %s
----------------
nikic wrote:

You need to use `-O2 -Xclang -disable-llvm-optzns`, or manually drop the `optnone` attributes.

https://github.com/llvm/llvm-project/pull/70845