Ice for PHP Formula was removed
Last version was
php56-ice requires the following formulae to be installed:
autoconf 2.69 Automatic configure script builder
ice 3.7.0_2 Comprehensive RPC framework

Recent formula history

ilovezfs php56: migrate to homebrew/core (#4835)
Mike McQuaid php56-ice: use <<~EOS.
Joe George php{56-71}-ice 3.7.0 (new formula)

Formula code at GitHub