[llvm] [DAG][PatternMatch] Add support for matchers with flags; NFC (PR #103060)

[Min-Yih Hsu via llvm-commits]

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@@ -695,6 +726,13 @@ template <typename Opnd> inline UnaryOpc_match<Opnd> m_ZExt(const Opnd &Op) {
   return UnaryOpc_match<Opnd>(ISD::ZERO_EXTEND, Op);
 }
 
+template <typename Opnd>
+inline UnaryOpc_match<Opnd> m_NNegZExt(const Opnd &Op) {
+  SDNodeFlags Flags{};
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mshockwave wrote:

nit: IIUC since SDNodeFlags has a user-provided default ctor, the value initialization here will eventually fallback to default initialization, which means it's the same as `SDNodeFlags Flags;`. Maybe we can use the latter instead.

ditto for other occurrences in this PR.

https://github.com/llvm/llvm-project/pull/103060