clang-modernize -use-nullptr

and s/\bNULL\b/nullptr/g for *.cpp/h/mm files not compiled on my machine

Source/Core/VideoBackends/D3D/D3DBlob.h

@@ -16,7 +16,7 @@ class D3DBlob
 {
 public:
 	// memory will be copied into an own buffer
-	D3DBlob(unsigned int blob_size, const u8* init_data = NULL);
+	D3DBlob(unsigned int blob_size, const u8* init_data = nullptr);
 
 	// d3dblob will be AddRef'd
 	D3DBlob(ID3D10Blob* d3dblob);