Looking at the inform code, it looks like V6 is not correctly
supported, in that it sets function addresses and string addresses to
paddr * 8, if I'm not mistaken, and doesn't change the main routine
header field, nor fill in the extra offset header fields.
V7 appears to use
(code_extra_offset + paddr) * 4 and
(strings_extra_offset + paddr) * 4
for code and strings respectively, but is otherwise identical to V5.
V8 appears to be set the addresses to just paddr * 8, and is otherwise
identical to V5.
Is this right?