General: Replace NULL and '0' usages with nullptr where applicable

src/citra_qt/debugger/callstack.h

@@ -12,7 +12,7 @@ class CallstackWidget : public QDockWidget
     Q_OBJECT
 
 public:
-    CallstackWidget(QWidget* parent = 0);
+    CallstackWidget(QWidget* parent = nullptr);
 
 public slots:
     void OnDebugModeEntered();

src/citra_qt/debugger/graphics.h

@@ -37,7 +37,7 @@ class GPUCommandStreamWidget : public QDockWidget
     Q_OBJECT
 
 public:
-    GPUCommandStreamWidget(QWidget* parent = 0);
+    GPUCommandStreamWidget(QWidget* parent = nullptr);
 
 private:
 };

src/citra_qt/debugger/graphics_cmdlists.h

@@ -41,7 +41,7 @@ class GPUCommandListWidget : public QDockWidget
     Q_OBJECT
 
 public:
-    GPUCommandListWidget(QWidget* parent = 0);
+    GPUCommandListWidget(QWidget* parent = nullptr);
 
 public slots:
     void OnToggleTracing();

src/citra_qt/debugger/profiler.h

@@ -37,7 +37,7 @@ class ProfilerWidget : public QDockWidget
     Q_OBJECT
 
 public:
-    ProfilerWidget(QWidget* parent = 0);
+    ProfilerWidget(QWidget* parent = nullptr);
 
 private slots:
     void setProfilingInfoUpdateEnabled(bool enable);

src/citra_qt/debugger/ramview.h

@@ -9,7 +9,7 @@ class GRamView : public QHexEdit
     Q_OBJECT
 
 public:
-    GRamView(QWidget* parent = NULL);
+    GRamView(QWidget* parent = nullptr);
 
 public slots:
     void OnCPUStepped();

src/citra_qt/debugger/registers.h

@@ -15,7 +15,7 @@ class RegistersWidget : public QDockWidget
     Q_OBJECT
 
 public:
-    RegistersWidget(QWidget* parent = NULL);
+    RegistersWidget(QWidget* parent = nullptr);
 
 public slots:
     void OnDebugModeEntered();