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/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
index 615d35b..c846818 100644
--- a/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
+++ b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
@@ -8,6 +8,8 @@
 
 #include "x86AssemblyInspectionEngine.h"
 
+#include <memory>
+
 #include "llvm-c/Disassembler.h"
 
 #include "lldb/Core/Address.h"
@@ -1172,7 +1174,7 @@
       *new_row = *original_last_row;
       new_row->SetOffset(offset);
       unwind_plan.AppendRow(new_row);
-      row.reset(new UnwindPlan::Row());
+      row = std::make_shared<UnwindPlan::Row>();
       *row = *new_row;
       reinstate_unwind_state = false;
       unwind_plan_updated = true;