Interpreter_LoadStore: No-op dcbt and dcbtst if HID0.NOOPTI is set

If HID0.NOOPTI is set, then dcbt and dcbtst are no-oped globally. We
currently don't perform data cache emulation, but we put this in anyway
so this detail isn't forgotten about if data cache emulation is
introduced at some point in the future.

Source/Core/Core/PowerPC/Interpreter/Interpreter_LoadStore.cpp

@@ -499,11 +499,17 @@ void Interpreter::dcbst(UGeckoInstruction inst)
 
 void Interpreter::dcbt(UGeckoInstruction inst)
 {
+  if (HID0.NOOPTI)
+    return;
+
   // TODO: Implement some sort of L2 emulation.
 }
 
 void Interpreter::dcbtst(UGeckoInstruction inst)
 {
+  if (HID0.NOOPTI)
+    return;
+
   // TODO: Implement some sort of L2 emulation.
 }