Fix old-style Mac platform detection in generate-json.py
Fix old-style Mac platform detection in generate-json.py

aksareen/balrog,tieu/balrog,mozbhearsum/balrog,nurav/balrog,aksareen/balrog,mozbhearsum/balrog,tieu/balrog,tieu/balrog,mozbhearsum/balrog,nurav/balrog,aksareen/balrog,aksareen/balrog,testbhearsum/balrog,tieu/balrog,testbhearsum/balrog,nurav/balrog,testbhearsum/balrog,nurav/balrog,testbhearsum/balrog,mozbhearsum/balrog