This patch adds the ability to dump array words. The words are only
dumped if they appear in a $dumpvars() statement (they are not dumped
by default). The name used for the word is <array_name>[<index>], so
you can get unexpected name conflicts.
There is also a slight increase in the memory requirements since each
array word now keeps its own name information. In the future we would
like to change this, but that is a much larger rewrite of the array
code in vvp.
This patch also needs the "Prefix escaped identifier ..." patch to
work correctly (the array word name is an escaped identifier).