System: Reset code cache on fastmem mode change

Fixes excess backpatching and potential crashes when changing mode.

src/core/settings.cpp

@@ -1012,7 +1012,7 @@ void Settings::FixIncompatibleSettings(bool display_osd_messages)
   }
 #endif
 
-  // fastmem should be off if we're not using the intepreter, save the allocation
+  // fastmem should be off if we're not using the recompiler, save the allocation
   if (g_settings.cpu_execution_mode != CPUExecutionMode::Recompiler)
     g_settings.cpu_fastmem_mode = CPUFastmemMode::Disabled;
 

src/core/system.cpp

@@ -4338,6 +4338,8 @@ void System::CheckForSettingsChanges(const Settings& old_settings)
     {
       // Reallocate fastmem area, even if it's not being used.
       Bus::RemapFastmemViews();
+      CPU::CodeCache::Reset();
+      InterruptExecution();
     }
 
     SPU::GetOutputStream()->SetOutputVolume(GetAudioOutputVolume());