Revert "[lldb] Fix dynamic_cast by no longer failing on variable without metadata"

This reverts commit b448d1bf212219febbb182d00c210bad1bd25e7f.

llvm-svn: 368615
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp b/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
index b7d8487..faac0c1 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
@@ -1265,10 +1265,16 @@
     clang::NamedDecl *named_decl = DeclForGlobal(global_variable);
 
     if (!named_decl) {
+      if (IsObjCSelectorRef(llvm_value_ptr))
+        return true;
+
+      if (!global_variable->hasExternalLinkage())
+        return true;
+
       LLDB_LOG(log, "Found global variable \"{0}\" without metadata",
                global_variable->getName());
 
-      return true;
+      return false;
     }
 
     llvm::StringRef name(named_decl->getName());