[470599]Revert "Use an index for xRefs Setting to pick addUnique faster"

This reverts commit 1495c2d9258553dfa6564bcfe1597f112bb1aab1 to get back
to the original state before applying the fix proposed in the EMF
project.


Bug: 470599
Change-Id: I070a2a81e5f5d8dc2eda8384f2c8f595c8fea5dc
Signed-off-by: Cedric Brun <cedric.brun@obeo.fr>
4 files changed