Fix the build with c++03.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186198 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-ar/llvm-ar.cpp b/tools/llvm-ar/llvm-ar.cpp
index 34663c2..ab2a2f1 100644
--- a/tools/llvm-ar/llvm-ar.cpp
+++ b/tools/llvm-ar/llvm-ar.cpp
@@ -379,10 +379,8 @@
 class NewArchiveIterator {
   bool IsNewMember;
   SmallString<16> MemberName;
-  union {
-    object::Archive::child_iterator OldI;
-    std::vector<std::string>::const_iterator NewI;
-  };
+  object::Archive::child_iterator OldI;
+  std::vector<std::string>::const_iterator NewI;
 
 public:
   NewArchiveIterator(object::Archive::child_iterator I, Twine Name);