Revert "unique_ptr-ify ownership of ASTConsumers"

This reverts commit r213307.

Reverting to have some on-list discussion/confirmation about the ongoing
direction of smart pointer usage in the LLVM project.

llvm-svn: 213325
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 7e4ffb1..7cea9e4 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -101,8 +101,8 @@
   TheSema.reset(S);
 }
 
-void CompilerInstance::setASTConsumer(std::unique_ptr<ASTConsumer> Value) {
-  Consumer = std::move(Value);
+void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
+  Consumer.reset(Value);
 }
 
 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {