This commit adds the definitions for `dyld_chained_starts_in_image`,
`dyld_chained_starts_in_segment`, and related enums. Dumping their
contents is possible with the -chained_fixups flag of llvm-otool.
The chained-fixups.yaml test was changed to cover bindings/rebases, as
well as weak imports, weak symbols and flat namespace symbols. Now that
we have actual fixup entries, the __DATA segment contains data that
would need to be hexdumped in YAML. We also test empty pages (to look
for the "DYLD_CHAINED_PTR_START_NONE" annotation), so the YAML would end
up quite large. So instead, this commit includes a binary file.
When Apple's effort to upstream their chained fixups code continues,
we'll replace this code with the then-upstreamed code. But we need
something in the meantime for testing ld64.lld's chained fixups code.
Differential Revision: https://reviews.llvm.org/D131961
