I seem to be losing track, I thought you made an additional install of 32bit Slackware.
No matter ...
Since it is the Java interpreter that is segfaulting, I would try a different Java - - -
Maybe try the 32bit build or maybe try the IBM build.
(You can have them all installed at the same time.)
I can't recall if I ever did run Eclipse with a 64bit Java myself.
My notes from the last time I used Eclipse:
http://minimodding.com/eclipse_tour