cmd/readall: add --syntax to check for valid Ruby.
cmd/readall: add --syntax to check for valid Ruby.

gregory-nisbet/brew,hanxue/linuxbrew,zmwangx/brew,bfontaine/brew,mahori/brew,mistydemeo/homebrew,jmsundar/brew,gordonmcshane/homebrew,MikeMcQuaid/brew,mistydemeo/homebrew,pseudocody/brew,nandub/brew,alyssais/brew,JCount/brew,AnastasiaSulyagina/brew,MikeMcQuaid/brew,Linuxbrew/brew,pseudocody/brew,EricFromCanada/brew,MikeMcQuaid/brew,gregory-nisbet/brew,MikeMcQuaid/brew,reitermarkus/brew,EricFromCanada/brew,DomT4/brew,mgrimes/brew,rwhogg/brew,Homebrew/brew,palxex/brew,amar-laksh/brew_sudo,aw1621107/brew,bfontaine/brew,muellermartin/dist,vitorgalvao/brew,claui/brew,DomT4/brew,palxex/brew,maxim-belkin/brew,gregory-nisbet/brew,claui/brew,jmsundar/brew,konqui/brew,aw1621107/brew,konqui/brew,tonyg/homebrew,rwhogg/brew,mahori/brew,reelsense/brew,ilovezfs/brew,staticfloat/brew,sjackman/homebrew,hanxue/linuxbrew,Homebrew/brew,DomT4/brew,vitorgalvao/brew,alyssais/brew,muellermartin/dist,JCount/brew,ilovezfs/brew,gordonmcshane/homebrew,gordonmcshane/homebrew,bfontaine/brew,amar-laksh/brew_sudo,jmsundar/brew,reelsense/brew,AnastasiaSulyagina/brew,mahori/brew,mgrimes/brew,EricFromCanada/brew,DomT4/brew,maxim-belkin/brew,Linuxbrew/brew,zmwangx/brew,maxim-belkin/brew,amar-laksh/brew_sudo,AnastasiaSulyagina/brew,mgrimes/brew,JCount/brew,reitermarkus/brew,claui/brew,konqui/brew,toonetown/homebrew,sjackman/homebrew,toonetown/homebrew,muellermartin/dist,palxex/brew,reitermarkus/brew,claui/brew,aw1621107/brew,tonyg/homebrew,staticfloat/brew,JCount/brew,staticfloat/brew,rwhogg/brew,EricFromCanada/brew,nandub/brew,alyssais/brew,toonetown/homebrew,Homebrew/brew,Linuxbrew/brew,vitorgalvao/brew,nandub/brew,hanxue/linuxbrew,tonyg/homebrew,reitermarkus/brew,mahori/brew,vitorgalvao/brew,konqui/brew,nandub/brew,reelsense/brew,zmwangx/brew,Linuxbrew/brew,sjackman/homebrew,sjackman/homebrew,pseudocody/brew,Homebrew/brew,ilovezfs/brew,mistydemeo/homebrew