Mostly complete tracing. Probably a lot of bugs.

src/xenia/cpu/xenon_thread_state.h

@@ -14,6 +14,11 @@
 #include <alloy/runtime/thread_state.h>
 #include <xenia/core.h>
 
+namespace xdb {
+namespace protocol {
+struct Registers;
+}  // namespace protocol
+}  // namespace xdb
 
 namespace xe {
 namespace cpu {
@@ -34,6 +39,8 @@ public:
   uint64_t thread_state_address() const { return thread_state_address_; }
   PPCContext* context() const { return context_; }
 
+  void WriteRegisters(xdb::protocol::Registers* registers);
+
 private:
   uint64_t  stack_address_;
   size_t    stack_size_;