[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/Analysis/MemorySSA.cpp b/llvm/lib/Analysis/MemorySSA.cpp
index ed4b645..26e3cd7 100644
--- a/llvm/lib/Analysis/MemorySSA.cpp
+++ b/llvm/lib/Analysis/MemorySSA.cpp
@@ -1238,7 +1238,7 @@
   auto Res = PerBlockAccesses.insert(std::make_pair(BB, nullptr));
 
   if (Res.second)
-    Res.first->second = llvm::make_unique<AccessList>();
+    Res.first->second = std::make_unique<AccessList>();
   return Res.first->second.get();
 }
 
@@ -1246,7 +1246,7 @@
   auto Res = PerBlockDefs.insert(std::make_pair(BB, nullptr));
 
   if (Res.second)
-    Res.first->second = llvm::make_unique<DefsList>();
+    Res.first->second = std::make_unique<DefsList>();
   return Res.first->second.get();
 }
 
@@ -1555,10 +1555,10 @@
 
   if (!WalkerBase)
     WalkerBase =
-        llvm::make_unique<ClobberWalkerBase<AliasAnalysis>>(this, AA, DT);
+        std::make_unique<ClobberWalkerBase<AliasAnalysis>>(this, AA, DT);
 
   Walker =
-      llvm::make_unique<CachingWalker<AliasAnalysis>>(this, WalkerBase.get());
+      std::make_unique<CachingWalker<AliasAnalysis>>(this, WalkerBase.get());
   return Walker.get();
 }
 
@@ -1568,10 +1568,10 @@
 
   if (!WalkerBase)
     WalkerBase =
-        llvm::make_unique<ClobberWalkerBase<AliasAnalysis>>(this, AA, DT);
+        std::make_unique<ClobberWalkerBase<AliasAnalysis>>(this, AA, DT);
 
   SkipWalker =
-      llvm::make_unique<SkipSelfWalker<AliasAnalysis>>(this, WalkerBase.get());
+      std::make_unique<SkipSelfWalker<AliasAnalysis>>(this, WalkerBase.get());
   return SkipWalker.get();
  }
 
@@ -2256,7 +2256,7 @@
                                                  FunctionAnalysisManager &AM) {
   auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
   auto &AA = AM.getResult<AAManager>(F);
-  return MemorySSAAnalysis::Result(llvm::make_unique<MemorySSA>(F, &AA, &DT));
+  return MemorySSAAnalysis::Result(std::make_unique<MemorySSA>(F, &AA, &DT));
 }
 
 bool MemorySSAAnalysis::Result::invalidate(