As a class's ivars are built up by inheritance, but with only that
class's ivars in the symbol table, is is necessary to include an offset
based on the super class's ivars in order to ensure alignments are
respected. This is achieved via the new `base` parameter to
build_struct(), which is used to offset the current size while
calculating the aligned offset of the symbols. The parameter is ignored
for unions, as they always start at 0. The ivars for the current class
still have a base offset of 0 until they are actually added to the
class.
Fixes#29
Since there is now a proper symbol table, defs are now just references to
memory locations and the symbol table takes care of duplicates.
Also, start using far data for ObjQC structures.
The qfo functions have been stubbed out until I figure out what to do with
object files in the new scheme.
That which isn't rewritten is horribly broken. However, this does include a
nice mechanism for building QC structs for emitting data.
emit.c has been gutted in the spirit of "throw one away".
There is much work to be done to get even variables emitted, let alone
code. Things should be a little more fun from here on.
