Document how to run profile/release from Xcode #51673
Description
In order to get Xcode use the correct debug/profile/release mode, the Generated.xcconfig file should include FLUTTER_BUILD_MODE=xxx.
A correct one would like like:
// This is a generated file; do not edit or check into version control.
FLUTTER_ROOT=/Users/liyuqian/flutter/flutter
FLUTTER_APPLICATION_PATH=/Users/liyuqian/flutter/test/webp
FLUTTER_TARGET=/Users/liyuqian/flutter/test/webp/lib/main.dart
FLUTTER_BUILD_DIR=build
SYMROOT=${SOURCE_ROOT}/../build/ios
FLUTTER_FRAMEWORK_DIR=/Users/liyuqian/flutter/flutter/bin/cache/artifacts/engine/ios-profile
FLUTTER_BUILD_NAME=1.0.0
FLUTTER_BUILD_NUMBER=1
TRACK_WIDGET_CREATION=true
FLUTTER_BUILD_MODE=profile
However, currently the Flutter tools are generating
// This is a generated file; do not edit or check into version control.
FLUTTER_ROOT=/Users/liyuqian/flutter/flutter
FLUTTER_APPLICATION_PATH=/Users/liyuqian/flutter/test/webp
FLUTTER_TARGET=/Users/liyuqian/flutter/test/webp/lib/main.dart
FLUTTER_BUILD_DIR=build
SYMROOT=${SOURCE_ROOT}/../build/ios
FLUTTER_FRAMEWORK_DIR=/Users/liyuqian/flutter/flutter/bin/cache/artifacts/engine/ios-profile
FLUTTER_BUILD_NAME=1.0.0
FLUTTER_BUILD_NUMBER=1
TRACK_WIDGET_CREATION=true