Bump bundled libarchive version to 3.5.2

- Update bunlded libarchive version used on Windows/Mac
- Enable requested zstd support while we are at it. Closes #211

dependencies/zstd-1.5.0/contrib/pzstd/utils/test/ResourcePoolTest.cpp

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "utils/ResourcePool.h"
+
+#include <gtest/gtest.h>
+#include <atomic>
+#include <thread>
+
+using namespace pzstd;
+
+TEST(ResourcePool, FullTest) {
+  unsigned numCreated = 0;
+  unsigned numDeleted = 0;
+  {
+    ResourcePool<int> pool(
+      [&numCreated] { ++numCreated; return new int{5}; },
+      [&numDeleted](int *x) { ++numDeleted; delete x; });
+
+    {
+      auto i = pool.get();
+      EXPECT_EQ(5, *i);
+      *i = 6;
+    }
+    {
+      auto i = pool.get();
+      EXPECT_EQ(6, *i);
+      auto j = pool.get();
+      EXPECT_EQ(5, *j);
+      *j = 7;
+    }
+    {
+      auto i = pool.get();
+      EXPECT_EQ(6, *i);
+      auto j = pool.get();
+      EXPECT_EQ(7, *j);
+    }
+  }
+  EXPECT_EQ(2, numCreated);
+  EXPECT_EQ(numCreated, numDeleted);
+}
+
+TEST(ResourcePool, ThreadSafe) {
+  std::atomic<unsigned> numCreated{0};
+  std::atomic<unsigned> numDeleted{0};
+  {
+    ResourcePool<int> pool(
+      [&numCreated] { ++numCreated; return new int{0}; },
+      [&numDeleted](int *x) { ++numDeleted; delete x; });
+    auto push = [&pool] {
+      for (int i = 0; i < 100; ++i) {
+        auto x = pool.get();
+        ++*x;
+      }
+    };
+    std::thread t1{push};
+    std::thread t2{push};
+    t1.join();
+    t2.join();
+
+    auto x = pool.get();
+    auto y = pool.get();
+    EXPECT_EQ(200, *x + *y);
+  }
+  EXPECT_GE(2, numCreated);
+  EXPECT_EQ(numCreated, numDeleted);
+}