This change adds boilerplate code to implement the object::ObjectFile
interface for the DXContainer object file and an empty implementation of
the objdump Dumper object.
Adding an ObjectFile implementation for DXContainer is a bit odd because
the DXContainer format doesn't have a symbol table, so there isn't a
reasonable implementation for the SymbolicFile interfaces. That said, it
does have sections, and it will be useful for objdump to be able to
inspect some of the structured data stored in some of the special named
sections.
At this point in the implementation it can't do much other than dump the
part names, offsets, and sizes. Dumping detailed structured section
contents to be extended in subsequent PRs.
Fixes#151433
2fe96439fb