In internal linking mode, allow an unresolved reference to
	<local>, assuming it will be resolved by a dynamic library
	symbol. The optional <remote> specifies the symbol's name and
	possibly version in the dynamic library, and the optional "<library>"
	names the specific library where the symbol should be found.

	On AIX, the library pattern is slightly different. It must be

	paxHdrs = make(map[string]string)

	var whyNoUSTAR, whyNoPAX, whyNoGNU string
	var preferPAX bool // Prefer PAX over USTAR
	verifyString := func(s string, size int, name, paxKey string) {
		// NUL-terminator is optional for path and linkpath.
		// Technically, it is required for uname and gname,
		// but neither GNU nor BSD tar checks for it.
		tooLong := len(s) > size
		allowLongGNU := paxKey == paxPath || paxKey == paxLinkpath

			wantErr error
		}
		testClose struct { // Close() == wantErr
			wantErr error
		}
		testFnc any // testHeader | testWrite | testReadFrom | testClose
	)

	vectors := []struct {
		file  string // Optional filename of expected output
		tests []testFnc
	}{{
		// The writer test file was produced with this command:
		// tar (GNU tar) 1.26
		//   ln -s small.txt link.txt