Common/DebugInterface: Default virtual destructor

While we're at it, we can also default the constructor and destructor of
inheriting classes in their respective cpp file to prevent the
construction and destruction of non-trivial types being inlined into
other regions of code.

Source/Core/Common/DebugInterface.h

@@ -18,7 +18,7 @@ namespace Common
 class DebugInterface
 {
 protected:
-  virtual ~DebugInterface() {}
+  virtual ~DebugInterface() = default;
 
 public:
   // Watches

Source/Core/Core/Debugger/PPCDebugInterface.cpp

@@ -44,6 +44,9 @@ void PPCPatches::Patch(std::size_t index)
   }
 }
 
+PPCDebugInterface::PPCDebugInterface() = default;
+PPCDebugInterface::~PPCDebugInterface() = default;
+
 std::size_t PPCDebugInterface::SetWatch(u32 address, std::string name)
 {
   return m_watches.SetWatch(address, std::move(name));

Source/Core/Core/Debugger/PPCDebugInterface.h

@@ -20,7 +20,9 @@ private:
 class PPCDebugInterface final : public Common::DebugInterface
 {
 public:
-  PPCDebugInterface() {}
+  PPCDebugInterface();
+  ~PPCDebugInterface() override;
+
   // Watches
   std::size_t SetWatch(u32 address, std::string name = "") override;
   const Common::Debug::Watch& GetWatch(std::size_t index) const override;

Source/Core/Core/HW/DSPLLE/DSPDebugInterface.cpp

@@ -20,6 +20,9 @@ void DSPPatches::Patch(std::size_t index)
   PanicAlert("Patch functionality not supported in DSP module.");
 }
 
+DSPDebugInterface::DSPDebugInterface() = default;
+DSPDebugInterface::~DSPDebugInterface() = default;
+
 std::size_t DSPDebugInterface::SetWatch(u32 address, std::string name)
 {
   return m_watches.SetWatch(address, std::move(name));

Source/Core/Core/HW/DSPLLE/DSPDebugInterface.h

@@ -21,7 +21,9 @@ private:
 class DSPDebugInterface final : public Common::DebugInterface
 {
 public:
-  DSPDebugInterface() {}
+  DSPDebugInterface();
+  ~DSPDebugInterface() override;
+
   // Watches
   std::size_t SetWatch(u32 address, std::string name = "") override;
   const Common::Debug::Watch& GetWatch(std::size_t index) const override;