Resolves: tdf#136364 treat svSep type with ocUnion as range type

Resolves: tdf#136364 treat svSep type with ocUnion as range type

So for RPN
sv...Ref(ocPush), sv...Ref(ocPush), svSep(ocUnion), sv...Ref(ocPush)
another svSep(ocUnion) instead of svSep(ocSep) is appended.

Regression from

    commit a6032ff5418ad66cc8fec10c636e32b124ee7864
    CommitDate: Thu Oct 11 11:26:37 2018 +0200

        Resolves: tdf#90698 catch list (1;2) of non-references as error

that introduced a conditional check on operands and operators.

Reviewed-on: https://gerrit.libreoffice.org/c/core/+/102276
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins
(cherry picked from commit e00e2be30436b636d93f8852bb6af44972638a7c)

Change-Id: If5da3a781f24f891ff12c4a8f32a2ec92c6b4c8a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/102279
Tested-by: Jenkins
Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>