./configure --disable-threads --enable-extras --enable-icuio --enable-layout
make && make install
Then checkout latest PHP and configure it --with-icu-dir=<dir> option, where
<dir> was the dir to where you installed ICU. You don't need to
explicitly use this option if you install ICU to a standard location.
The constants below are defined by this extension, and
will only be available when the extension has either
been compiled into PHP or dynamically loaded at runtime.