arch,base,cpu,kerm,sim: Build a symbol table for object files.

arch,base,cpu,kerm,sim: Build a symbol table for object files.

Instead of calling into object files after the fact and asking them to
put symbols into a target symbol table, this change makes object files
fill in a symbol table themselves at construction. Then, that table can
be retrieved and used to fill in aggregate tables, masked, moved,
and/or filtered to have only one type of symbol binding.

This simplifies the symbol management API of the object file types
significantly, and makes it easier to deal with symbol tables alongside
binaries in the FS workload classes.

Change-Id: Ic9006ca432033d72589867c93d9c5f8a1d87f73c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24787
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>