[gn] Extract target_os, target_cpu resolution (#33238)
[gn] Extract target_os, target_cpu resolution (#33238)


rmacnak-google/engine,rmacnak-google/engine,rmacnak-google/engine,devoncarew/engine,devoncarew/engine,chinmaygarde/flutter_engine,flutter/engine,flutter/engine,rmacnak-google/engine,flutter/engine,chinmaygarde/flutter_engine,chinmaygarde/flutter_engine,flutter/engine,chinmaygarde/flutter_engine,flutter/engine,devoncarew/engine,chinmaygarde/flutter_engine,devoncarew/engine,devoncarew/engine,rmacnak-google/engine,flutter/engine,flutter/engine,flutter/engine,chinmaygarde/flutter_engine,chinmaygarde/flutter_engine,devoncarew/engine,rmacnak-google/engine,rmacnak-google/engine,devoncarew/engine