[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/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 098343c..a386330 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -1296,12 +1296,12 @@
 
       // Separate out the producers and target features sections
       if (Name == "producers") {
-        ProducersSection = llvm::make_unique<WasmCustomSection>(Name, &Section);
+        ProducersSection = std::make_unique<WasmCustomSection>(Name, &Section);
         continue;
       }
       if (Name == "target_features") {
         TargetFeaturesSection =
-            llvm::make_unique<WasmCustomSection>(Name, &Section);
+            std::make_unique<WasmCustomSection>(Name, &Section);
         continue;
       }
 
@@ -1618,5 +1618,5 @@
 std::unique_ptr<MCObjectWriter>
 llvm::createWasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW,
                              raw_pwrite_stream &OS) {
-  return llvm::make_unique<WasmObjectWriter>(std::move(MOTW), OS);
+  return std::make_unique<WasmObjectWriter>(std::move(MOTW), OS);
 }