Each row contains unwinding rules for a set of registers.
Fields
offset: u64 = 0,
Offset from FrameDescriptionEntry.pc_begin
cfa: Column = .{ },
Special-case column that defines the CFA (Canonical Frame Address) rule. The register field of this column defines the register that CFA is derived from.
columns: ColumnRange = .{ },
The register fields in these columns define the register the rule applies to.
copy_on_write: bool = false,
Indicates that the next write to any column in this row needs to copy the backing column storage first, as it may be referenced by previous rows.