unbreak PHP highlighting

The php files are auto-generated and there seems to be some magic
about IncludeRules here. Modelines needs to be excluded here.

This issue appeared two weeks ago and is in no public release.

You may need to remove build/part/syntax/data/*.xml in order to
regenerate the xml files. Otherwise, the old ones and the bug
just persists.

CCMAIL: i.zaufi@gmail.com
BUG: 318465