[Fix java build] Stop using non standard std::make_unique

Summary: std::make_unique is not standard and not always available, remove it

Test Plan: Run "make clean jclean rocksdbjava jtest -j8" on my mac

Reviewers: yhchiang, yiwu, sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61143

java/rocksjni/options.cc

@@ -1104,7 +1104,8 @@ std::vector<rocksdb::CompressionType> rocksdb_compression_vector_helper(
  */
 jbyteArray rocksdb_compression_list_helper(JNIEnv* env,
     std::vector<rocksdb::CompressionType> compressionLevels) {
-  std::unique_ptr<jbyte[]> jbuf = std::make_unique<jbyte[]>(compressionLevels.size());
+  std::unique_ptr<jbyte[]> jbuf =
+      std::unique_ptr<jbyte[]>(new jbyte[compressionLevels.size()]);
   for (std::vector<rocksdb::CompressionType>::size_type i = 0;
         i != compressionLevels.size(); i++) {
       jbuf[i] = compressionLevels[i];

java/rocksjni/rocksjni.cc

@@ -115,7 +115,8 @@ jlongArray rocksdb_open_helper(JNIEnv* env, jlong jopt_handle,
   // check if open operation was successful
   if (s.ok()) {
     jsize resultsLen = 1 + len_cols; //db handle + column family handles
-    std::unique_ptr<jlong[]> results = std::make_unique<jlong[]>(resultsLen);
+    std::unique_ptr<jlong[]> results =
+        std::unique_ptr<jlong[]>(new jlong[resultsLen]);
     results[0] = reinterpret_cast<jlong>(db);
     for(int i = 1; i <= len_cols; i++) {
       results[i] = reinterpret_cast<jlong>(handles[i - 1]);

java/rocksjni/ttl.cc

@@ -96,7 +96,8 @@ jlongArray
   // check if open operation was successful
   if (s.ok()) {
     jsize resultsLen = 1 + len_cols; //db handle + column family handles
-    std::unique_ptr<jlong[]> results = std::make_unique<jlong[]>(resultsLen);
+    std::unique_ptr<jlong[]> results =
+        std::unique_ptr<jlong[]>(new jlong[resultsLen]);
     results[0] = reinterpret_cast<jlong>(db);
     for(int i = 1; i <= len_cols; i++) {
       results[i] = reinterpret_cast<jlong>(handles[i - 1]);