PR13100: build tracepoint query modules separately, concurrently

PR13100: build tracepoint query modules separately, concurrently

* tapsets.cxx (tracepoint_extra_decls): Prepare for PR13155.
  (get_tracepoint_modules): Rewrite former get_tracepoint_module().
  (tracepoint_builder::init_dw): Don't even try to build all tracequery
  modules at once.
* buildrun.cxx (make_tracequeries): Replace make_tracequery().
  Run given compilation jobs in parallel.
* buildrun.h: Corresponding changes.
* hash.cxx (find_tracequery_hash): Clarify signature for single header.
* hash.h: Corresponding changes.