Some Makefiles have "debug", "d", "release", and "r" for build targets. Others also include "dev", "develop", "development", "dep", "deploy", and "deployment". Because of this inconsistency, trying to use those additional targets didn't work. It looks like all Makefiles used to support all of those targets, but some got dropped along the way. For instance, the top-level Makefile and Source/Makefile dropped them in 2013 as part of Bug 107863. And it looks like WebKitLibraries/Makefile never had them. Given that those additional targets don't work, it seems like no one uses them, so let's remove them completely.
<rdar://problem/69407746>
Created attachment 409443 [details] Patch
Committed r267458: <https://trac.webkit.org/changeset/267458> All reviewed patches have been landed. Closing bug and clearing flags on attachment 409443 [details].