I've added the reserved field as an "optional" in YAML, but I've added asserts in the yaml2macho code to enforce that the field is present in mach_header_64, but not in mach_header.
llvm-svn: 269320
Since we want to be able to use yaml to describe degenerate object files as well as valid ones, we need to be explicit of some fields in your yaml definitions.
llvm-svn: 269313