ControllerInterface: Add RemoveDevice()

This adds RemoveDevice() to ControllerInterface, fixes ExpressionParser
and some other code to support device removals without crashing,
and adds an IsValid() method to Device, to prepare for hotplugging.

Source/Core/Core/HW/GCKeyboardEmu.cpp

@@ -86,6 +86,7 @@ std::string GCKeyboard::GetName() const
 
 void GCKeyboard::GetInput(KeyboardStatus* const kb)
 {
+  auto lock = ControllerEmu::GetStateLock();
   m_keys0x->GetState(&kb->key0x, keys0_bitmasks);
   m_keys1x->GetState(&kb->key1x, keys1_bitmasks);
   m_keys2x->GetState(&kb->key2x, keys2_bitmasks);

Source/Core/Core/HW/GCPadEmu.cpp

@@ -81,6 +81,8 @@ std::string GCPad::GetName() const
 
 void GCPad::GetInput(GCPadStatus* const pad)
 {
+  auto lock = ControllerEmu::GetStateLock();
+
   ControlState x, y, triggers[2];
 
   // buttons
@@ -116,6 +118,7 @@ void GCPad::GetInput(GCPadStatus* const pad)
 
 void GCPad::SetOutput(const ControlState strength)
 {
+  auto lock = ControllerEmu::GetStateLock();
   m_rumble->controls[0]->control_ref->State(strength);
 }
 
@@ -190,5 +193,6 @@ void GCPad::LoadDefaults(const ControllerInterface& ciface)
 
 bool GCPad::GetMicButton() const
 {
+  auto lock = ControllerEmu::GetStateLock();
   return (0.0f != m_buttons->controls.back()->control_ref->State());
 }

Source/Core/Core/HW/WiimoteEmu/WiimoteEmu.cpp

@@ -623,8 +623,11 @@ void Wiimote::Update()
     return;
 
   // returns true if a report was sent
-  if (Step())
-    return;
+  {
+    auto lock = ControllerEmu::GetStateLock();
+    if (Step())
+      return;
+  }
 
   u8 data[MAX_PAYLOAD];
   memset(data, 0, sizeof(data));
@@ -646,6 +649,8 @@ void Wiimote::Update()
     data[0] = 0xA1;
     data[1] = m_reporting_mode;
 
+    auto lock = ControllerEmu::GetStateLock();
+
     // core buttons
     if (rptf.core)
       GetButtonData(data + rptf.core);
@@ -876,6 +881,7 @@ void Wiimote::ConnectOnInput()
   }
 
   u16 buttons = 0;
+  auto lock = ControllerEmu::GetStateLock();
   m_buttons->GetState(&buttons, button_bitmasks);
   m_dpad->GetState(&buttons, dpad_bitmasks);
 

Source/Core/Core/HotkeyManager.cpp

@@ -240,6 +240,7 @@ std::string HotkeyManager::GetName() const
 
 void HotkeyManager::GetInput(HotkeyStatus* const kb)
 {
+  auto lock = ControllerEmu::GetStateLock();
   for (int set = 0; set < (NUM_HOTKEYS + 31) / 32; set++)
   {
     std::vector<u32> bitmasks;