erts: Make trace:info not block schedulers for call_time/memory

Instead use this strategy

0. Seize code mod permission (as before)
1. Allocate temporary zeroed hashes for any traced calls that may happen
   during the call to trace:info.
2. Thread progress
3. Switch bp index to make the temp hashes active.
4. Thread progress.
5. Collect stats from the real hashes that are now unused and stable.
6. Switch back bp index to make the real hashes active again.
7. Thread progress.
8. Consolidate by collecting stats from the temp hashes into the
   active generation.
9. Deallocate the temp hashes and make the two halves of the breakpoint
   identical again using the same real hashes.
10. Build result from stats collected in step 5
11. Release code mod permission

Author: sverker

erts/emulator/beam/atom.names

@@ -744,6 +744,7 @@ atom total_run_queue_lengths_all
 atom tpkt
 atom trace traced
 atom trace_control_word
+atom trace_info_finish
 atom trace_status
 atom tracer
 atom trap_exit