rts: Turn ASSERT in LDV_recordDead into a normal if
As reported in #15382 the ASSERT(ctr != NULL)
is currently getting routinely
hit during testsuite runs. While this is certainly a bug I would far prefer
getting a proper error message than a segmentation fault. Consequently I'm
turning the ASSERT
into a proper if
so we get a proper error in non-debug
builds.