Roll Clang 214024:216630 (+216684) and switch to CMake

tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp

Index: tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
diff --git a/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp b/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
index 0ad2ff6b7d4d621852ea716fcd0897bf42ba5a9a..e37c40aad06d4b7451f28db4040a910bfa766ad7 100644
--- a/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
+++ b/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
@@ -1606,9 +1606,10 @@ class BlinkGCPluginAction : public PluginASTAction {
 
  protected:
   // Overridden from PluginASTAction:
-  virtual ASTConsumer* CreateASTConsumer(CompilerInstance& instance,
-                                         llvm::StringRef ref) {
-    return new BlinkGCPluginConsumer(instance, options_);
+  virtual std::unique_ptr<ASTConsumer> CreateASTConsumer(
+      CompilerInstance& instance,
+      llvm::StringRef ref) {
+    return llvm::make_unique<BlinkGCPluginConsumer>(instance, options_);
   }
 
   virtual bool ParseArgs(const CompilerInstance& instance,