use 2 threads for random type check tests (saves about a minute in type_check_SUITE)
use 2 threads for random type check tests (saves about a minute in type_check_SUITE)

l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror