Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146959 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 439a124..6ef07c4 100644
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -411,6 +411,8 @@
   ParseAST(CI.getSema(), CI.getFrontendOpts().ShowStats);
 }
 
+void PluginASTAction::anchor() { }
+
 ASTConsumer *
 PreprocessorFrontendAction::CreateASTConsumer(CompilerInstance &CI,
                                               StringRef InFile) {