ENGINES: Silence clang warning about unused private member _vm

This affects the Console / debugger classes of multiple engines.
An alternative solution would have been to remove the unused _vm
member vars. However, it seems likely that in the future, the _vm
member could be useful for methods added to the console. So instead,
we add a simple assert(_vm) to silence the clang warning.

engines/cine/console.cpp

@@ -28,6 +28,7 @@ namespace Cine {
 bool labyrinthCheat;
 
 CineConsole::CineConsole(CineEngine *vm) : GUI::Debugger(), _vm(vm) {
+	assert(_vm);
 	DCmd_Register("labyrinthCheat", WRAP_METHOD(CineConsole, Cmd_LabyrinthCheat));
 
 	labyrinthCheat = false;

engines/draci/console.cpp

@@ -26,6 +26,7 @@
 namespace Draci {
 
 DraciConsole::DraciConsole(DraciEngine *vm) : GUI::Debugger(), _vm(vm) {
+	assert(_vm);
 }
 
 DraciConsole::~DraciConsole() {

engines/dreamweb/console.cpp

@@ -25,6 +25,7 @@
 namespace DreamWeb {
 
 DreamWebConsole::DreamWebConsole(DreamWebEngine *vm) : GUI::Debugger(), _vm(vm) {
+	assert(_vm);
 }
 
 DreamWebConsole::~DreamWebConsole() {

engines/made/console.cpp

@@ -26,6 +26,7 @@
 namespace Made {
 
 MadeConsole::MadeConsole(MadeEngine *vm) : GUI::Debugger(), _vm(vm) {
+	assert(_vm);
 }
 
 MadeConsole::~MadeConsole() {

engines/sword1/console.cpp

@@ -26,6 +26,7 @@
 namespace Sword1 {
 
 SwordConsole::SwordConsole(SwordEngine *vm) : GUI::Debugger(), _vm(vm) {
+	assert(_vm);
 }
 
 SwordConsole::~SwordConsole() {

engines/sword25/console.cpp

@@ -26,6 +26,7 @@
 namespace Sword25 {
 
 Sword25Console::Sword25Console(Sword25Engine *vm) : GUI::Debugger(), _vm(vm) {
+	assert(_vm);
 }
 
 Sword25Console::~Sword25Console() {

engines/toon/console.cpp

@@ -26,6 +26,7 @@
 namespace Toon {
 
 ToonConsole::ToonConsole(ToonEngine *vm) : GUI::Debugger(), _vm(vm) {
+	assert(_vm);
 }
 
 ToonConsole::~ToonConsole() {

engines/tucker/console.cpp

@@ -11,7 +11,7 @@
 
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
  * GNU General Public License for more details.
 
  * You should have received a copy of the GNU General Public License
@@ -26,6 +26,7 @@
 namespace Tucker {
 
 TuckerConsole::TuckerConsole(TuckerEngine *vm) :  _vm(vm) {
+	assert(_vm);
 }
 
 TuckerConsole::~TuckerConsole() {