Work around for correct treatment of all-vs-all

Neither C or accelerated all-vs-all kernels work in 4.6. The group
SIMD kernels do not work either. The non-accelerated kernel is OK,
though.

Fixes #1249 (for certain values of "fixes"), refs #1095

Change-Id: Id52c0ba110aa915e77859585c2cbfd4d529fe3ca