[Clang] 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.

Differential revision: https://reviews.llvm.org/D66259

llvm-svn: 368942
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 3c23e43..4f0e20b 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -2049,7 +2049,7 @@
   }
 
   std::unique_ptr<CorrectionCandidateCallback> clone() override {
-    return llvm::make_unique<VarDeclFilterCCC>(*this);
+    return std::make_unique<VarDeclFilterCCC>(*this);
   }
 
 };
@@ -2071,7 +2071,7 @@
   }
 
   std::unique_ptr<CorrectionCandidateCallback> clone() override {
-    return llvm::make_unique<VarOrFuncDeclFilterCCC>(*this);
+    return std::make_unique<VarOrFuncDeclFilterCCC>(*this);
   }
 };