Promote the Arg union to a core data type in Object.c such
that it is visible everywhere (many source files need it),
and correct declarations of several functions that use it.
The Process_sendSignal function is also corrected to have
the expected return type (bool, not void) - an error being
masked by ignoring this not-quite-harmless warning. I've
also added error checking to the kill(2) call here, which
was previously overlooked / missing (?).
disable useless code in release builds such as runtime type-checking on
dynamic data structures and process fields that are not being computed,
faster(?) method for verifying the process owner (still need to ensure
correctness), don't destroy and create process objects for hidden kernel
threads over and over. Phew. I shouldn't be doing all this today, but I
could not resist.
