Debugger: Add a Thread widget

DebugInterface: Add GetThreads

WatchWidget: Update widget on AddWatch

Source/Core/Common/Debug/Threads.h

@@ -0,0 +1,63 @@
+// Copyright 2020 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "Common/CommonTypes.h"
+
+namespace Common::Debug
+{
+struct PartialContext
+{
+  std::optional<std::array<u32, 32>> gpr;
+  std::optional<u32> cr;
+  std::optional<u32> lr;
+  std::optional<u32> ctr;
+  std::optional<u32> xer;
+  std::optional<std::array<double, 32>> fpr;
+  std::optional<u64> fpscr;
+  std::optional<u32> srr0;
+  std::optional<u32> srr1;
+  std::optional<u16> dummy;
+  std::optional<u16> state;
+  std::optional<std::array<u32, 8>> gqr;
+  std::optional<std::array<double, 32>> psf;
+};
+
+class ThreadView
+{
+public:
+  virtual ~ThreadView() = default;
+
+  enum class API
+  {
+    OSThread,   // Nintendo SDK thread
+    LWPThread,  // devkitPro libogc thread
+  };
+
+  virtual PartialContext GetContext() const = 0;
+  virtual u32 GetAddress() const = 0;
+  virtual u16 GetState() const = 0;
+  virtual bool IsSuspended() const = 0;
+  virtual bool IsDetached() const = 0;
+  virtual s32 GetBasePriority() const = 0;
+  virtual s32 GetEffectivePriority() const = 0;
+  virtual u32 GetStackStart() const = 0;
+  virtual u32 GetStackEnd() const = 0;
+  virtual std::size_t GetStackSize() const = 0;
+  virtual s32 GetErrno() const = 0;
+  // Implementation specific, used to store arbitrary data
+  virtual std::string GetSpecific() const = 0;
+  virtual bool IsValid() const = 0;
+};
+
+using Threads = std::vector<std::unique_ptr<ThreadView>>;
+
+}  // namespace Common::Debug