[lld] [lld][WebAssembly] Allow `--trace-symbol` to work with symbols with custom import names (PR #96119)

[Heejin Ahn via llvm-commits]

================
@@ -526,6 +535,7 @@ Symbol *SymbolTable::addUndefinedFunction(StringRef name,
     printTraceSymbolUndefined(name, file);
 
   auto replaceSym = [&]() {
+    traceImport(importName, file);
----------------
aheejin wrote:

This `replaceSym` also seems to be called when `wasInserted` was not true below:
```cpp
      // If the existing undefined functions is not called directly then let
      // this one take precedence.  Otherwise the existing function is either
      // directly called or defined, in which case we need a function variant.
      if (existingUndefined && !existingUndefined->isCalledDirectly)
        replaceSym();
      else if (getFunctionVariant(s, sig, file, &s))
        replaceSym();
```
Is that OK to run this again in this case?

https://github.com/llvm/llvm-project/pull/96119