[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/ExecutionEngine/Orc/LegacyRTDyldObjectLinkingLayerTest.cpp b/llvm/unittests/ExecutionEngine/Orc/LegacyRTDyldObjectLinkingLayerTest.cpp
index 001019d..3f0f85b 100644
--- a/llvm/unittests/ExecutionEngine/Orc/LegacyRTDyldObjectLinkingLayerTest.cpp
+++ b/llvm/unittests/ExecutionEngine/Orc/LegacyRTDyldObjectLinkingLayerTest.cpp
@@ -75,7 +75,7 @@
       });
 
   LLVMContext Context;
-  auto M = llvm::make_unique<Module>("", Context);
+  auto M = std::make_unique<Module>("", Context);
   M->setTargetTriple("x86_64-unknown-linux-gnu");
   Type *Int32Ty = IntegerType::get(Context, 32);
   GlobalVariable *GV =