5.3.4: bit rot with ruby-1.8.6 bindings

[Jeff Johnson]

The Mi class fails running ruby/trb like this:
....

--> Mi.rb
       ack($mi.instance_of?(Mi)) got 'true'
       ack($mi.kind_of?(Mi)) got 'true'
       ack($mi.class.to_s) got 'Mi'
       ack($mi.debug = 1;) got '1'
       ack($mi.debug = 0;) got '0'
       ack($mi.length) got '1'
       ack($mi.count) got '1'
       ack($mi.instance) got '0'
       ack($mi.pattern($RPMTAG_NAME, $N)) got 'true'
       ack($mi.instance) got '0'
NACK: ack($h['name']) caught 'undefined method `[]' for nil:NilClass'

...

There's further bit rot in the Hdr, Ds, and Fi classes.