[llvm] [llvm] Use llvm::append_range (NFC) (PR #135931)

[Jakub Kuderski via llvm-commits]

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@@ -1320,7 +1320,7 @@ class CfiFunctionIndex {
   std::vector<StringRef> symbols() const {
     std::vector<StringRef> Symbols;
     for (auto &[GUID, Syms] : Index)
-      Symbols.insert(Symbols.end(), Syms.begin(), Syms.end());
+      llvm::append_range(Symbols, Syms);
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kuhar wrote:

Maybe prefix it with `_`, i.e., `_GUID` to make it clear that it's intended to be unused? Or alternatively, use `(void)GUID;`?

https://github.com/llvm/llvm-project/pull/135931