threads resolved for the last build; 1 means serial.
Test-only count of threads the engine's last permutation build opened; 1 = serial.
What makes any Stage 4 threading test non-vacuous. The permutation is bit-identical
at every thread count -- the comparator is a total order, so there is exactly one
correct answer -- which means no assertion on perm can distinguish a threaded run
from a serial one. A policy that silently refuses to thread is therefore invisible
to every other test in the suite, and is the easiest Stage 4 bug to write.
Reports the RESOLVED count, not the team the runtime actually granted. Has no effect on, and says nothing about, the C++ engine.