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

lldb/source/Plugins/Process/Utility/ThreadMemory.cpp

@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "Plugins/Process/Utility/ThreadMemory.h"
+
 #include "Plugins/Process/Utility/RegisterContextThreadMemory.h"
 #include "lldb/Target/OperatingSystem.h"
 #include "lldb/Target/Process.h"
@@ -15,6 +16,8 @@
 #include "lldb/Target/StopInfo.h"
 #include "lldb/Target/Unwind.h"
 
+#include <memory>
+
 using namespace lldb;
 using namespace lldb_private;
 
@@ -44,8 +47,8 @@ void ThreadMemory::ClearStackFrames() {
 
 RegisterContextSP ThreadMemory::GetRegisterContext() {
   if (!m_reg_context_sp)
-    m_reg_context_sp.reset(
-        new RegisterContextThreadMemory(*this, m_register_data_addr));
+    m_reg_context_sp = std::make_shared<RegisterContextThreadMemory>(
+        *this, m_register_data_addr);
   return m_reg_context_sp;
 }