Fix String#start_with? implementation
Fix String#start_with? implementation

It is supposed to accept a variable number of prefixes, and also to
check if they are convertible to strings. This matches behavior
documented in RubySpec.

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