Add support for a "load binary" LC_NOTE in mach-o corefiles

Add lldb support for a Mach-O "load binary" LC_NOTE which provides
a UUID, load address/slide, and possibly a name of a binary that
should be loaded when examining the core.

struct load_binary
{
    uint32_t version;        // currently 1
    uuid_t   uuid;           // all zeroes if uuid not specified
    uint64_t load_address;   // virtual address where the macho is loaded, UINT64_MAX if unavail
    uint64_t slide;          // slide to be applied to file address to get load address, 0 if unavail
    char     name_cstring[]; // must be nul-byte terminated c-string, '\0' alone if name unavail
} __attribute__((packed));

Differential Revision: https://reviews.llvm.org/D115494
rdar://85069250