Auto merge of #122140 - oli-obk:track_errors13, r=davidtwco

Run a single huge par_body_owners instead of many small ones after each other.

This improves parallel rustc parallelism by avoiding the bottleneck after each individual `par_body_owners` (because it needs to wait for queries to finish, so if there is one long running one, a lot of cores will be idle while waiting for the single query).

Author: bors