illumos gate

From Keith's original bug description.

There are a small number of components on which illumos-joyent encodes runtime dependencies at build time, and which are not delivered by illumos, illumos-extra, or anything else in our build environment. These dependencies need to be eliminated or integrated into illumos, but in the meantime the mechanism that has been used is to inject them into the build machine itself via fake-subset. This is functional but unfortunate in a number of ways. It would be preferable to carry a hopefully declining set of library and header adjuncts that the illumos (and other components') build system can be told to use. This allows one to cross cross-consolidation flag days without changing one's build zone, and creates a clear inventory of everything on which the build is expected to encode runtime dependencies (so that they can be eliminated one by one).

This requires relatively modest changes to the illumos build system. A separate ticket will cover an auditing tool for creating an inventory of files referenced by the build outside the source tree, proto area, and adjunct directory.