Kernel/IPC: Partially implement MappedBuffer translation.

Right now only MappedBuffers that only span a single page and are not aligned are implemented.

MappedBuffers are unmapped during the reply part of ReplyAndReceive. Only unmapping of ReadOnly buffers is currently implemented.

src/core/hle/kernel/ipc.h

@@ -10,5 +10,5 @@
 namespace Kernel {
 /// Performs IPC command buffer translation from one process to another.
 ResultCode TranslateCommandBuffer(SharedPtr<Thread> src_thread, SharedPtr<Thread> dst_thread,
-                                  VAddr src_address, VAddr dst_address);
+                                  VAddr src_address, VAddr dst_address, bool reply);
 } // namespace Kernel