Same as readLink, except it asserts the path is absolute.
On Windows, path should be encoded as WTF-8.
On WASI, path should be encoded as valid UTF-8.
On other platforms, path is an opaque sequence of bytes with no particular encoding.
pub fn readLinkAbsolute(io: Io, absolute_path: []const u8, buffer: []u8) ReadLinkError!usize
pub fn readLinkAbsolute(io: Io, absolute_path: []const u8, buffer: []u8) ReadLinkError!usize {
assert(path.isAbsolute(absolute_path));
return io.vtable.dirReadLink(io.userdata, .cwd(), absolute_path, buffer);
}