[clang-tools-extra] [clang-doc] fix flaky test in clang-doc (PR #101387)

[Paul Kirth via cfe-commits]

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@@ -312,6 +317,16 @@ struct SymbolInfo : public Info {
 
   std::optional<Location> DefLoc;     // Location where this decl is defined.
   llvm::SmallVector<Location, 2> Loc; // Locations where this decl is declared.
+
+  bool operator<(const SymbolInfo &Other) const {
+    if (DefLoc && Other.DefLoc) {
+      return *DefLoc < *Other.DefLoc;
+    }
+    if (Loc.size() > 0 && Other.Loc.size() > 0) {
+      return Loc[0] < Other.Loc[0];
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ilovepi wrote:

Again, what if these are equal?

https://github.com/llvm/llvm-project/pull/101387