The extended complex NRM2 tests can compare an expected +Inf norm with
a computed +Inf norm. The relative-error path then evaluates Inf - Inf,
producing NaN and reporting a spurious failure.
Treat exactly equal results as zero test ratio before computing the
relative difference. This matches the existing SNRM2 and DNRM2 test
logic.
Fixes#1047.
Aymen Qader
6af853258b