array type name mangling

In connection with completing David Fetter's array of composites patch,
I am looking at doing some better name mangling for array types as
recently discussed. What I'm thinking of is prepending one or more
underscores to the type name up to some limit (NAMEDATALEN / 2 ?) and if
necessary truncating the result, and then looking to see if there is a
name clash. That would, I hope, enable us to get rid of all the places
where we require names to be no more than NAMEDATALEN - 2 chars. Does
that seem like a reasonable approach? Will it break anything, i.e., is
there somewhere that has assumes the array type for foo will be called
_foo rather than ___foo ?

cheers

andrew