[clang] fixed clang frontend crash with friend class declaration and overload == (PR #133878)

[via cfe-commits]

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@@ -285,3 +285,15 @@ struct j {
 };
 bool j::operator==(const j &) const = default;
 }
+
+namespace evil2 {
+  struct k {
+  };
+  
+  struct l {
+      friend bool operator==(const l& a, const l& b);
+      friend class k;
+  };
+  
+  bool operator==(const l& a, const l& b) = default;
+}
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cor3ntin wrote:

Missing new line

https://github.com/llvm/llvm-project/pull/133878