Use std::make_shared in LLDB (NFC)

Unlike std::make_unique, which is only available since C++14,
std::make_shared is available since C++11. Not only is std::make_shared
a lot more readable compared to ::reset(new), it also performs a single
heap allocation for the object and control block.

Differential revision: https://reviews.llvm.org/D57990

llvm-svn: 353764
diff --git a/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp b/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp
index 6dca6b6..513bdb3 100644
--- a/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp
+++ b/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp
@@ -29,6 +29,8 @@
 
 #include "SystemRuntimeMacOSX.h"
 
+#include <memory>
+
 using namespace lldb;
 using namespace lldb_private;
 
@@ -495,9 +497,9 @@
           bool stop_id_is_valid = true;
           if (item.stop_id == 0)
             stop_id_is_valid = false;
-          originating_thread_sp.reset(new HistoryThread(
+          originating_thread_sp = std::make_shared<HistoryThread>(
               *m_process, item.enqueuing_thread_id, item.enqueuing_callstack,
-              item.stop_id, stop_id_is_valid));
+              item.stop_id, stop_id_is_valid);
           originating_thread_sp->SetExtendedBacktraceToken(
               item.item_that_enqueued_this);
           originating_thread_sp->SetQueueName(
@@ -540,9 +542,9 @@
       bool stop_id_is_valid = true;
       if (item.stop_id == 0)
         stop_id_is_valid = false;
-      return_thread_sp.reset(new HistoryThread(
+      return_thread_sp = std::make_shared<HistoryThread>(
           *m_process, item.enqueuing_thread_id, item.enqueuing_callstack,
-          item.stop_id, stop_id_is_valid));
+          item.stop_id, stop_id_is_valid);
       return_thread_sp->SetExtendedBacktraceToken(item.item_that_enqueued_this);
       return_thread_sp->SetQueueName(item.enqueuing_queue_label.c_str());
       return_thread_sp->SetQueueID(item.enqueuing_queue_serialnum);
@@ -567,10 +569,10 @@
   if (queue_item_sp->GetStopID() == 0)
     stop_id_is_valid = false;
 
-  extended_thread_sp.reset(
-      new HistoryThread(*m_process, queue_item_sp->GetEnqueueingThreadID(),
-                        queue_item_sp->GetEnqueueingBacktrace(),
-                        queue_item_sp->GetStopID(), stop_id_is_valid));
+  extended_thread_sp = std::make_shared<HistoryThread>(
+      *m_process, queue_item_sp->GetEnqueueingThreadID(),
+      queue_item_sp->GetEnqueueingBacktrace(), queue_item_sp->GetStopID(),
+      stop_id_is_valid);
   extended_thread_sp->SetExtendedBacktraceToken(
       queue_item_sp->GetItemThatEnqueuedThis());
   extended_thread_sp->SetQueueName(queue_item_sp->GetQueueLabel().c_str());