[lld] [ELF] Fix unnecessary inclusion of unreferenced provide symbols (PR #84512)

[Fangrui Song via llvm-commits]

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@@ -201,12 +201,7 @@ static bool shouldDefineSym(SymbolAssignment *cmd) {
   if (!cmd->provide)
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MaskRay wrote:

`return !cmd->provide || LinkerScript::shouldAddProvideSym(cmd->name);`

https://github.com/llvm/llvm-project/pull/84512