Fix for Coverity perl5 CID 29032: Out-of-bounds read (OVERRUN) overrun-local: Overrun...

Fix for Coverity perl5 CID 29032: Out-of-bounds read (OVERRUN) overrun-local: Overrunning array anyofs of 34 8-byte elements at element index 34 (byte offset 272) using index index (which evaluates to 34).

Off-by-one error: because the test "index > number of elements"
should have used ">=", the anyofs[] could have been accessed one
past the end.  Use the C_ARRAY_LENGTH since we have it.
I think regprop is only used by -Mre=debug.