[FaultsMaps][llvm-objdump] Move FaultMapParser to Object/. Remove CodeGen dependency from llvm-objdump
FaultsMapParser lived in CodeGen and was forcing llvm-objdump to
link CodeGen and everything CodeGen depends on.
This was previously attempted in r240364 to fix a link failure.
The CodeGen dependency was independently added to fix the same
link failure, and that ended up being kept.
Removing the dependency seems like the correct layering for
Reviewed By: MaskRay, jhenderson
Differential Revision: https://reviews.llvm.org/D95414