[lld] [LLD][COFF] Add support for ARM64X same-address thunks (PR #151255)

[Jacek Caban via llvm-commits]

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@@ -2668,12 +2677,46 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
     createECExportThunks();
 
   // Resolve remaining undefined symbols and warn about imported locals.
+  std::vector<Undefined *> aliases;
   ctx.forEachSymtab(
-      [&](SymbolTable &symtab) { symtab.resolveRemainingUndefines(); });
+      [&](SymbolTable &symtab) { symtab.resolveRemainingUndefines(aliases); });
 
   if (errorCount())
     return;
 
+  ctx.forEachActiveSymtab([](SymbolTable &symtab) {
+    symtab.initializeECThunks();
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cjacek wrote:

`initializeECThunks()` already checks the machine type, so the previous check was redundant.

https://github.com/llvm/llvm-project/pull/151255