Refactor SVC handler (#540)

* Refactor SVC handler

* Get rid of KernelErr

* Split kernel code files into multiple folders

Ryujinx.HLE/HOS/Kernel/Memory/KMemoryArrangeRegion.cs

@@ -0,0 +1,16 @@
+namespace Ryujinx.HLE.HOS.Kernel.Memory
+{
+    struct KMemoryArrangeRegion
+    {
+        public ulong Address { get; private set; }
+        public ulong Size    { get; private set; }
+
+        public ulong EndAddr => Address + Size;
+
+        public KMemoryArrangeRegion(ulong address, ulong size)
+        {
+            Address = address;
+            Size    = size;
+        }
+    }
+}