This PR makes verification of .debug_names acceleration table
multithreaded. In local testing it improves verification of clang
.debug_names from four minutes to under a minute.
This PR relies on a current mechanism of extracting DIEs into a vector.
Future improvements can include creating API to extract one DIE at a
time, or grouping Entires into buckets by CUs and extracting before
parallel step.
Single Thread
4:12.37 real, 246.88 user, 3.54 sys, 0 amem,10232004 mmem
Multi Thread
0:49.40 real, 612.84 user, 515.73 sys, 0 amem, 11226292 mmem
4f902d2425