[RFC] adding a variable to .mk and Makefile.inc1 to point to top of the FreeBSD source tree

[Simon J. Gerraty]

>> Do you mean why not simply use ${MACHINE}.${MACHINE_ARCH} always?
>> Encoding both MACHINE and MACHINE_ARCH always is doable, but I avoid =
>'.'

Actually I only avoid '.' in the captured dirdeps.
So ${MACHINE}.${MACHINE_ARCH} in objdir may be ok - will take a look.

Dealing with ${MACHINE}.${MACHINE_ARCH} is actually easy it just gets
stripped from the captured dirdeps, it is references to other machine
and arch's that need to be captured but cannot be dealt with as neatly.
The vast majority of such cases though are for pseudo machines like
"host" and "common" (for generated files which are machine
independent) where the issue shouldn't arise anyway.