[llvm] [SelectionDAG] Add m_Neg and m_Not pattern matcher and update DAGCombiner (PR #85365)

[Matt Arsenault via llvm-commits]

================
@@ -705,6 +705,18 @@ inline auto m_False() {
       },
       m_Value()};
 }
+
+/// Match a negtive as a sub(0, v)
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arsenm wrote:

```suggestion
/// Match a negate as a sub(0, v)
```

https://github.com/llvm/llvm-project/pull/85365