MFC r257530
MFC r257530

Reimplement r257525 such that it work with the historic FreeBSD make
implementation.  This fixes the toolchain and kernel-toolchain targets
when building from older FreeBSD versions where make is fmake.

Sponsored by:	DARPA/AFRL
Approved by:	re (glebius)

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase