[FaultsMaps][llvm-objdump] Move FaultMapParser to Object/. Remove CodeGen...

[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
llvm-objdump.

Reviewed By: MaskRay, jhenderson

Differential Revision: https://reviews.llvm.org/D95414