Tune GC RTS options for tests

Description

Problem: we run tests with -N and default options for GC. It is known that by default GHC's GC has a very small allocation area, meaning that GCs will occur too often, damaging test's run time.

Solution: increase allocation area by using the recommended -A64m option. Also increase allocation area for large objects with -AL256m, since this area is shared between all threads and thus with high -N values get used up too soon. Also enable -eventlog just in case we need to debug test performance in the future.

Related issue(s)

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