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

[via llvm-commits]

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@@ -2659,6 +2659,58 @@ static void postParseObjectFile(ELFFileBase *file) {
   }
 }
 
+// Returns true if the provide symbol should be added to the link.
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partaror wrote:

Thank you for the suggestions. `LinkerScript` is a better place for these functions. I have moved the functions to `LinkerScript`. As a side-effect, I had to move the file static function `addUnusedUndefined` in `Driver.cpp` to the class `SymbolTable` because now both `Driver.cpp` and `LinkerScript.cpp` needed this function.

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