[llvm] Move a lot of symbol code to use the symbol string pool (PR #115796)

[Lang Hames via llvm-commits]

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@@ -35,6 +36,7 @@
 #include "llvm/TargetParser/Triple.h"
 #include <optional>
 
+#include <cstring>
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lhames wrote:

Why is `<cstring>` needed?

https://github.com/llvm/llvm-project/pull/115796