The only way I can see of doing it is by selecting 'Songs' and clicking on one to play, then when the little banner is at the bottom, click that so you see the art work and player, then there's the option at the bottom
If you select songs, and just click on a random song, you can click the shuffle button in the "Now Playing" menu. Same function, just less convenient to get started.
Thanks for the advice! That works although it seems inconvenient. My music habit is to have several artist specific Smart Playlists set with the rule of only playing songs/mixes I haven't heard in the past year - then I just shuffle all songs on the iphone... The thought I'd lost that option actually horrified me almost as much the last "Fix" advice I'd read: having to use Siri to get round it; I'm not standing in a crowded London Underground tube bellowing "Siri shuffle all my music" till she finally understands what I'm saying....!