NUL byte.

As Go doesn't have support for C's union type in the general case,
C's union types are represented as a Go byte array with the same length.

Go structs cannot embed fields with C types.

Go code cannot refer to zero-sized fields that occur at the end of
non-empty C structs. To get the address of such a field (which is the
only operation you can do with a zero-sized field) you must take the

</p>

<pre>
uint(-1)     // -1 cannot be represented as a uint
int(3.14)    // 3.14 cannot be represented as an int
int64(Huge)  // 1267650600228229401496703205376 cannot be represented as an int64
Four * 300   // operand 300 cannot be represented as an int8 (type of Four)
Four * 100   // product 400 cannot be represented as an int8 (type of Four)
</pre>

<p>

Asia/Srednekolymsk Asia/Taipei Asia/Tashkent Asia/Tbilisi Asia/Tehran Asia/Tel_Aviv Asia/Thimbu Asia/Thimphu Asia/Tokyo Asia/Tomsk Asia/Ujung_Pandang Asia/Ulaanbaatar Asia/Ulan_Bator Asia/Urumqi Asia/Ust-Nera Asia/Vientiane Asia/Vladivostok Asia/Yakutsk Asia/Yangon Asia/Yekaterinburg Asia/Yerevan Atlantic/Azores Atlantic/Bermuda Atlantic/Canary Atlantic/Cape_Verde Atlantic/Faeroe Atlantic/Faroe Atlantic/Jan_Mayen Atlantic/Madeira Atlantic/Reykjavik Atlantic/South_Georgia Atlantic/St_Helena Atlantic/Stanley Australia/ACT...

		if hasNUL(s) || (tooLong && !allowLongGNU) {
			whyNoGNU = fmt.Sprintf("GNU cannot encode %s=%q", name, s)
			format.mustNotBe(FormatGNU)
		}
		if !isASCII(s) || tooLong {
			canSplitUSTAR := paxKey == paxPath
			if _, _, ok := splitUSTARPath(s); !canSplitUSTAR || !ok {
				whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%q", name, s)
				format.mustNotBe(FormatUSTAR)
			}
			if paxKey == paxNone {

	FMOVD	0x8008(R1), F2		// FMOVD	32776(R1), F2		// 3b204091620740fd
	FMOVD	0x1006ff8(R1), F2	// FMOVD	16805880(R1), F2	// 3bfc7f9162ff7ffd

// very large or unaligned offset uses constant pool.
// the encoding cannot be checked as the address of the constant pool is unknown.
// here we only test that they can be assembled.
	MOVB	R1, 0x1000000(R2)	// MOVB		R1, 16777216(R2)
	MOVB	R1, 0x44332211(R2)	// MOVB		R1, 1144201745(R2)

which are tied to a specific release.
-->

## Introduction {#intro}

Go's emphasis on backwards compatibility is one of its key strengths.
There are, however, times when we cannot maintain complete compatibility.
If code depends on buggy (including insecure) behavior,
then fixing the bug will break that code.
New features can also have similar impacts:

var u1 = 1.0<<s != 0           // illegal: 1.0 has type float64, cannot shift
var u2 = 1<<s != 1.0           // illegal: 1 has type float64, cannot shift
var v1 float32 = 1<<s          // illegal: 1 has type float32, cannot shift
var v2 = string(1<<s)          // illegal: 1 is converted to a string, cannot shift

	}
	p.get(')')
	a.Type = obj.TYPE_MEM
	if r1 < 0 {
		// Pseudo-register reference.
		if r2 != 0 {
			p.errorf("cannot use pseudo-register in pair")
			return
		}
		// For SB, SP, and FP, there must be a name here. 0(FP) is not legal.
		if name != "PC" && a.Name == obj.NAME_NONE {
			p.errorf("cannot reference %s without a symbol", name)
		}
		p.setPseudoRegister(a, name, false, prefix)
		return
	}
	a.Reg = r1

//
// It panics if count is negative or if the result of (len(b) * count)
// overflows.
func Repeat(b []byte, count int) []byte {
	if count == 0 {
		return []byte{}
	}

	// Since we cannot return an error on overflow,
	// we should panic if the repeat will generate an overflow.
	// See golang.org/issue/16237.
	if count < 0 {
		panic("bytes: negative Repeat count")
	}
	if len(b) >= maxInt/count {

		if err != nil {
			return err
		}
		if d.IsDir() {
			return nil
		}
		info, err := d.Info()
		if err != nil {
			return err
		}
		if !info.Mode().IsRegular() {
			return errors.New("zip: cannot add non-regular file")
		}
		h, err := FileInfoHeader(info)
		if err != nil {
			return err
		}
		h.Name = name
		h.Method = Deflate
		fw, err := w.CreateHeader(h)
		if err != nil {
			return err