src/cmd/go.mod. When a package outside std or cmd is imported
by a package inside std or cmd, the import path is interpreted
as if it had a "vendor/" prefix. For example, within "crypto/tls",
an import of "golang.org/x/crypto/cryptobyte" resolves to
"vendor/golang.org/x/crypto/cryptobyte". When a package with the
same path is imported from a package outside std or cmd, it will

	<li>The scope of an identifier denoting a constant, type, variable,
	    or function (but not method) declared at top level (outside any
	    function) is the package block.</li>

	<li>The scope of the package name of an imported package is the file block
	    of the file containing the import declaration.</li>

// function (but not any function called by it) stops the panicking sequence
// by restoring normal execution and retrieves the error value passed to the
// call of panic. If recover is called outside the deferred function it will
// not stop a panicking sequence. In this case, or when the goroutine is not
// panicking, recover returns nil.
//
// Prior to Go 1.21, recover would also return nil if panic is called with

//	LMOVH rreg ',' rreg
//	{
//		outcode(int($1), &$2, 0, &$4);
//	}
	MOVH	R16, R27	// 0010dc00001bdc03
	MOVHU	R1, R3		// 3023ffff

//	LMOVB rreg ',' rreg
//	{
//		outcode(int($1), &$2, 0, &$4);
//	}
	MOVB	R8, R9		// 00084e0000094e03
	MOVBU	R12, R17	// 319100ff

//	LMOVV addr ',' rreg
//	{
//		outcode(int($1), &$2, 0, &$4);
//	}
	MOVV	foo<>+3(SB), R2

// found.
func findDirectory64End(r io.ReaderAt, directoryEndOffset int64) (int64, error) {
	locOffset := directoryEndOffset - directory64LocLen
	if locOffset < 0 {
		return -1, nil // no need to look for a header outside the file
	}
	buf := make([]byte, directory64LocLen)
	if _, err := r.ReadAt(buf, locOffset); err != nil {
		return -1, err
	}
	b := readBuf(buf)
	if sig := b.uint32(); sig != directory64LocSignature {

			p := IndexByte(b[i:i+15], byte(100+j))
			if p != j {
				t.Errorf("IndexByte(%q, %d) = %d", b[i:i+15], 100+j, p)
			}
		}
		for j := 0; j < 15; j++ {
			b[i+j] = 0
		}
	}
	// Make sure matches outside the slice never trigger.
	for i := 0; i <= len(b)-15; i++ {
		for j := 0; j < 15; j++ {
			b[i+j] = 1
		}
		for j := 0; j < 15; j++ {
			p := IndexByte(b[i:i+15], byte(0))
			if p != -1 {

	<li>The scope of an identifier denoting a constant, type, variable,
	    or function (but not method) declared at top level (outside any
	    function) is the package block.</li>

	<li>The scope of the package name of an imported package is the file block
	    of the file containing the import declaration.</li>

		if p.As == obj.ATEXT {
			text = p.From.Sym
		}
		hexes := hexByLine[p.Line()]
		if hexes == "" {
			continue
		}
		delete(hexByLine, p.Line())
		if text == nil {
			t.Errorf("%s: instruction outside TEXT", p)
		}
		size := int64(len(text.P)) - p.Pc
		if p.Link != nil {
			size = p.Link.Pc - p.Pc
		} else if p.Isize != 0 {
			size = int64(p.Isize)
		}
		var code []byte

//	{
//		outcode($1, $2, &$3, 0, &$5);
//	}
	ADD	$1, R2
	ADD	R1<<R2, R3
	ADD	R1>>R2, R3
	ADD	R1@>R2, R3
	ADD	R1->R2, R3
	ADD	R1, R2

//
// MVN
//
//	LTYPE2 cond imsr ',' reg
//	{
//		outcode($1, $2, &$3, 0, &$5);
//	}
	CLZ	R1, R2

//
// MOVW
//
//	LTYPE3 cond gen ',' gen
//	{
//		outcode($1, $2, &$3, 0, &$5);
//	}
	MOVW.S	R1, R2
	MOVW	$1, R2
	MOVW.S	R1<<R2, R3

//

	// files. Internally, the tar format often uses fake "files" to add meta
	// data that describes the next file. These meta data "files" should not
	// normally be visible to the outside. As such, this loop iterates through
	// one or more "header files" until it finds a "normal file".
	format := FormatUSTAR | FormatPAX | FormatGNU
	for {
		// Discard the remainder of the file and any padding.