Reapply fix for make_unique not supported by C++11 (pytorch#217)

Summary:
Pull Request resolved: pytorch#217

re-appling the fix to #PR 215

Reviewed By: jianyuh

Differential Revision: D18919069

fbshipit-source-id: cd9c94420b274e73cd0b33506d832176eb8bcfbb

bench/FP16Benchmark.cc

@@ -103,8 +103,8 @@ void performance_test(
 
     vector<unique_ptr<PackedGemmMatrixFP16>> Bp;
     for (int i = 0; i < num_instances; ++i) {
-      Bp.push_back(
-          make_unique<PackedGemmMatrixFP16>(btran, k, n, alpha, B.data()));
+      Bp.push_back(unique_ptr<PackedGemmMatrixFP16>(
+          new PackedGemmMatrixFP16(btran, k, n, alpha, B.data())));
     }
 
     auto kAligned = ((k * sizeof(float) + 64) & ~63) / sizeof(float);