[lld-macho] Accept dylibs with LC_DYLD_EXPORTS_TRIE

This load command specifies the offset and size of the exports trie.
This information used to be a field in LC_DYLD_INFO, but in newer
libraries, it has a dedicated load command: LC_DYLD_EXPORTS_TRIE.

The format of the trie is the same for both load commands, so the code
for parsing it can be shared.

LLD does not generate this yet; it is mainly useful when chained fixups
are in use, as the other members of LC_DYLD_INFO are unused then, so the
smaller LC_DYLD_EXPORTS_TRIE can be output instead.

LLDB gained support for this in D107673.

Fixes #54550

Differential Revision: https://reviews.llvm.org/D129430