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

[Lang Hames via llvm-commits]

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@@ -1415,10 +1454,10 @@ class LinkGraph {
   void makeAbsolute(Symbol &Sym, orc::ExecutorAddr Address) {
     assert(!Sym.isAbsolute() && "Symbol is already absolute");
     if (Sym.isExternal()) {
-      assert(ExternalSymbols.contains(Sym.getName()) &&
+      assert(ExternalSymbols.contains(*Sym.getName()) &&
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lhames wrote:

`ExternalSymbolMap` should become a `DenseMap<SymbolStringPtr, Symbol*>` to avoid the extra string comparisons, but that can be a FIXME / follow-up patch.

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