[llvm] Migrate llvm::make_unique to std::make_unique

Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
diff --git a/llvm/unittests/ADT/STLExtrasTest.cpp b/llvm/unittests/ADT/STLExtrasTest.cpp
index 8704ddd..4cbef90 100644
--- a/llvm/unittests/ADT/STLExtrasTest.cpp
+++ b/llvm/unittests/ADT/STLExtrasTest.cpp
@@ -451,7 +451,7 @@
   EXPECT_EQ(V1, to_address(V1));
 
   // Check fancy pointer overload for unique_ptr
-  std::unique_ptr<int> V2 = make_unique<int>(0);
+  std::unique_ptr<int> V2 = std::make_unique<int>(0);
   EXPECT_EQ(V2.get(), to_address(V2));
 
   V2.reset(V1);