USE="geoip" for PHP emerge?

[noisefactor]

On php.net I find an API for geoip, and there is a GeoIP package in gentoo. So why is there no use flag for this in the PHP build?

[ebuild R ] dev-lang/php-5.1.6-r6 USE="apache2 berkdb cli crypt gdbm iconv ipv6 ncurses nls pcre readline reflection session spl ssl unicode zlib -adabas -apache* -bcmath -birdstep -bzip2* -calendar* -cdb -cgi -cjk -concurrentmodphp -ctype -curl -curlwrappers -db2 -dbase -dbmaker -debug -discard-path -doc -empress -empress-bcs -esoob -exif -fastbuild -fdftk -filepro -firebird -flatfile* -force-cgi-redirect -frontbase -ftp -gd* -gd-external -gmp -hardenedphp -hash -hyperwave-api -imap -informix -inifile -interbase -iodbc -java-external -kerberos -ldap -libedit -mcve -memlimit -mhash -ming* -msql -mssql -mysql* -mysqli -oci8 -oci8-instant-client -odbc -pcntl -pdo -pdo-external -pic -posix -postgres -qdbm -recode -sapdb -sasl -sharedext -sharedmem -simplexml* -snmp -soap -sockets* -solid -spell* -sqlite -sybase -sybase-ct -sysvipc -threads -tidy* -tokenizer* -truetype* -vm-goto -vm-switch -wddx -xml* -xmlreader* -xmlrpc* -xmlwriter* -xpm* -xsl -yaz -zip*" 0 kB

[xces]