Fix Clang-tidy modernize-use-nullptr warnings in some files in source/Target; other minor fixes.

llvm-svn: 261242
diff --git a/lldb/source/Target/UnwindAssembly.cpp b/lldb/source/Target/UnwindAssembly.cpp
index af7f86f..3dc4435 100644
--- a/lldb/source/Target/UnwindAssembly.cpp
+++ b/lldb/source/Target/UnwindAssembly.cpp
@@ -1,4 +1,4 @@
-//===-- UnwindAssembly.cpp ------------------------------*- C++ -*-===//
+//===-- UnwindAssembly.cpp --------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,6 +7,10 @@
 //
 //===----------------------------------------------------------------------===//
 
+// C Includes
+// C++ Includes
+// Other libraries and framework includes
+// Project includes
 #include "lldb/lldb-private.h"
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Core/PluginInterface.h"
@@ -21,14 +25,14 @@
     UnwindAssemblyCreateInstance create_callback;
 
     for (uint32_t idx = 0;
-         (create_callback = PluginManager::GetUnwindAssemblyCreateCallbackAtIndex(idx)) != NULL;
+         (create_callback = PluginManager::GetUnwindAssemblyCreateCallbackAtIndex(idx)) != nullptr;
          ++idx)
     {
         UnwindAssemblySP assembly_profiler_ap (create_callback (arch));
-        if (assembly_profiler_ap.get ())
+        if (assembly_profiler_ap)
             return assembly_profiler_ap;
     }
-    return NULL;
+    return nullptr;
 }
 
 UnwindAssembly::UnwindAssembly (const ArchSpec &arch) :
@@ -36,6 +40,4 @@
 {
 }
 
-UnwindAssembly::~UnwindAssembly ()
-{
-}
+UnwindAssembly::~UnwindAssembly() = default;