Each row contains unwinding rules for a set of registers.
pub const Row = struct
pub const Row = struct {
/// Offset from `FrameDescriptionEntry.pc_begin`
offset: u64 = 0,
cfa: CfaRule = .none,
/// The register fields in these columns define the register the rule applies to.
columns: ColumnRange = .{ .start = undefined, .len = 0 },
}