[gn build] Port 3b6a8f8

Author: llvmgnsyncbot

llvm/utils/gn/secondary/lldb/source/Plugins/Platform/MacOSX/BUILD.gn

@@ -43,6 +43,7 @@ static_library("MacOSX") {
     "PlatformRemoteAppleBridge.cpp",
     "PlatformRemoteAppleTV.cpp",
     "PlatformRemoteAppleWatch.cpp",
+    "PlatformRemoteAppleXR.cpp",
     "PlatformRemoteDarwinDevice.cpp",
     "PlatformRemoteMacOSX.cpp",
     "PlatformRemoteiOS.cpp",