Notify debugger on BRK instruction

# Conflicts:
#	src/Ryujinx.HLE/Debugger/Debugger.cs
#	src/Ryujinx.HLE/Debugger/Message/ThreadBreakMessage.cs
#	src/Ryujinx.HLE/HOS/Kernel/Process/KProcess.cs

src/Ryujinx.HLE/Debugger/Debugger.cs

@@ -1,4 +1,4 @@
-using Ryujinx.Common;
+using Ryujinx.Common;
 using Ryujinx.Common.Logging;
 using Ryujinx.Memory;
 using System;
@@ -8,6 +8,7 @@ using System.Net;
 using System.Net.Sockets;
 using System.Text;
 using System.Threading;
+using IExecutionContext = Ryujinx.Cpu.IExecutionContext;
 
 namespace Ryujinx.HLE.Debugger
 {
@@ -134,6 +135,11 @@ namespace Ryujinx.HLE.Debugger
                         WriteStream.WriteByte((byte)'+');
                         ProcessCommand(cmd);
                         break;
+
+                    case ThreadBreakMessage msg:
+                        HaltApplication();
+                        Reply($"T05thread:{msg.Context.ThreadUid:x};");
+                        break;
                 }
             }
         }
@@ -641,5 +647,14 @@ namespace Ryujinx.HLE.Debugger
                 HandlerThread.Join();
             }
         }
+
+        public void ThreadBreak(IExecutionContext ctx, ulong address, int imm)
+        {
+            ctx.DebugStop();
+
+            Logger.Notice.Print(LogClass.GdbStub, $"Break hit on thread {ctx.ThreadUid} at pc {address:x016}");
+
+            Messages.Add(new ThreadBreakMessage(ctx, address, imm));
+        }
     }
 }

src/Ryujinx.HLE/Debugger/Message/ThreadBreakMessage.cs

@@ -0,0 +1,18 @@
+using IExecutionContext = Ryujinx.Cpu.IExecutionContext;
+
+namespace Ryujinx.HLE.Debugger
+{
+    public class ThreadBreakMessage : IMessage
+    {
+        public IExecutionContext Context { get; }
+        public ulong Address { get; }
+        public int Opcode { get; }
+
+        public ThreadBreakMessage(IExecutionContext context, ulong address, int opcode)
+        {
+            Context = context;
+            Address = address;
+            Opcode = opcode;
+        }
+    }
+}

src/Ryujinx.HLE/HOS/Kernel/Process/KProcess.cs

@@ -730,9 +730,16 @@ namespace Ryujinx.HLE.HOS.Kernel.Process
 
         public IExecutionContext CreateExecutionContext()
         {
+            ExceptionCallback breakCallback = null;
+
+            if (KernelContext.Device.Configuration.EnableGdbStub)
+            {
+                breakCallback = KernelContext.Device.Debugger.ThreadBreak;
+            }
+
             return Context?.CreateExecutionContext(new ExceptionCallbacks(
                 InterruptHandler,
-                null,
+                breakCallback,
                 KernelContext.SyscallHandler.SvcCall,
                 UndefinedInstructionHandler));
         }