fix: create empty metadata-bin files to satisfy XCode dep checks

Author: rigor789

v8ios.xcodeproj/project.pbxproj

@@ -1864,7 +1864,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "cd ${PROJECT_DIR}/metadata-generator/build/bin\ncp ../../build-step-metadata-generator.py .\n./build-step-metadata-generator.py\n";
+			shellScript = "cd ${PROJECT_DIR}/metadata-generator/build/bin\ncp ../../build-step-metadata-generator.py .\n./build-step-metadata-generator.py\n\n# create temporary empty metadata files for XCode LD/LDPLUSPLUS flag analysis\nfor arch in $VALID_ARCHS\ndo :\n    touch \"$CONFIGURATION_BUILD_DIR/metadata-$arch.bin\"\ndone\n";
 		};
 /* End PBXShellScriptBuildPhase section */