[lld] [lld] Merge GOT entries for symbols that have been ICFed (PR #131630)

[Peter Smith via llvm-commits]

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@@ -667,6 +667,19 @@ GotSection::GotSection(Ctx &ctx)
 void GotSection::addConstant(const Relocation &r) { relocations.push_back(r); }
 void GotSection::addEntry(const Symbol &sym) {
   assert(sym.auxIdx == ctx.symAux.size() - 1);
+  if (auto *d = dyn_cast<Defined>(&sym)) {
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smithp35 wrote:

I've only had a quick skim through this, so I don't know if what I'm suggesting would be better. I'm interested in your opinion. 

An alternative implementation would be to make sure that addEntry is not called on symbols that have been ICFed. I think this would mean moving this to postScanRelocations, potentially we could use the symbol::folded property and find the canonical unfolded definition?

https://github.com/llvm/llvm-project/pull/131630