COMPAT: Avoid queue pop_back usage in SVA

[ajeethakv]

Rule suggested by Ben Cohen:

IEEE LRM 1800 states:

16.6 Boolean expressions: “Elements of dynamic arrays, queues, and associative arrays that are sampled for assertion expression evaluation may get removed from the array or the array may get resized before the assertion expression is evaluated. These specific array elements sampled for assertion expression evaluation shall continue to exist within the scope of the assertion until the assertion expression evaluation completes.”

Many tools are slow to adopt this IEEE 1800 requirement. Several imposed restrictions on the use of queues within assertions, and some prohibited them entirely, likely due to performance concerns.

So avoid usage of q.pop_back in SVA expressions

e.g.
($rose(a) |-> (q.pop_back == 8'h08)