[lld][WebAssembly] Fix use after free of archive path

This was fixed in the ELF backend in https://reviews.llvm.org/D34554.

Differential Revision: https://reviews.llvm.org/D67676

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@372266 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/wasm/InputFiles.h b/wasm/InputFiles.h
index 2b25906..4a445a7 100644
--- a/wasm/InputFiles.h
+++ b/wasm/InputFiles.h
@@ -54,7 +54,7 @@
   Kind kind() const { return fileKind; }
 
   // An archive file name if this file is created from an archive.
-  StringRef archiveName;
+  std::string archiveName;
 
   ArrayRef<Symbol *> getSymbols() const { return symbols; }