This patch is extracted from D96035, it adds support for the accelerator
tables to the DWARFLinkerParallel functionality.
run-time performance and memory requirements for clang binary --num-threads 16 :
----------------------------------------------------------------------------------
                                                      |  time, sec   |  mem, GB  |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator Apple --linker llvm   |      55      |   20.0    |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator Apple --linker apple  |     263      |   23.0    |
----------------------------------------------------------------------------------run-time performance and memory requirements for clang binary --num-threads 1 :
----------------------------------------------------------------------------------
                                                      |  time, sec   |  mem, GB  |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator Apple --linker llvm   |     273      |   19.0    |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator Apple --linker apple  |     276      |   21.0    |
----------------------------------------------------------------------------------Depends on D153268
Document what the variant cases mean?