shims/linux/super/cc: ignore -liconv for Linuxbrew
shims/linux/super/cc: ignore -liconv for Linuxbrew

maxim-belkin/brew,maxim-belkin/brew,Linuxbrew/brew,hanxue/linuxbrew,rwhogg/brew,Linuxbrew/brew,rwhogg/brew,rwhogg/brew,hanxue/linuxbrew,maxim-belkin/brew,Linuxbrew/brew,Linuxbrew/brew,hanxue/linuxbrew