populateRanges

pub fn populateRanges(d: *Dwarf, gpa: Allocator, endian: Endian) ScanError!void {
    assert(d.ranges.items.len == 0);

    for (d.compile_unit_list.items, 0..) |*cu, cu_index| {
        if (cu.pc_range) |range| {
            try d.ranges.append(gpa, .{
                .start = range.start,
                .end = range.end,
                .compile_unit_index = cu_index,
            });
            continue;
        }
        const ranges_value = cu.die.getAttr(AT.ranges) orelse continue;
        var iter = DebugRangeIterator.init(ranges_value, d, endian, cu) catch continue;
        while (try iter.next()) |range| {
            // Not sure why LLVM thinks it's OK to emit these...
            if (range.start == range.end) continue;

            try d.ranges.append(gpa, .{
                .start = range.start,
                .end = range.end,
                .compile_unit_index = cu_index,
            });
        }
    }

    std.mem.sortUnstable(Range, d.ranges.items, {}, struct {
        pub fn lessThan(ctx: void, a: Range, b: Range) bool {
            _ = ctx;
            return a.start < b.start;
        }
    }.lessThan);
}