openldap isn't compiled with cyrus-sasl support ...there's a mistake in the ebuild Reproducible: Always Steps to Reproduce: 1. ldapsearch reports no cyrus-sasl support
Created attachment 28472 [details, diff] fixes cyrus-sasl activation now ldapsearch & Co reports cyrus-sasl support
your patch looks wrong to me. cyrus-sasl isn't a valid use flag. Do you have sasl in your use flags? Remember to always include the output of emerge --info in your bug reports as instructed on the bug submission page.
you should be using USE="sasl", USE="cyrus-sasl" is totally bogus.