// no holes in it). On the other hand, the zero value of sparseDatas implies
// that the file has no data in it, which is rather odd.
//
// As an example, if the underlying raw file contains the 10-byte data:
//
//	var compactFile = "abcdefgh"
//
// And the sparse map has the following entries:
//
//	var spd sparseDatas = []sparseEntry{

are also treated as invalid.
(Older toolchains ignore `//go:debug` directives entirely.)

The defaults that will be compiled into a main package
are reported by the command:

{{raw `
	go list -f '{{.DefaultGODEBUG}}' my/main/package
`}}

Only differences from the base Go toolchain defaults are reported.

When testing a package, `//go:debug` lines in the `*_test.go`

	b.uint16(h.ReaderVersion)
	b.uint16(h.Flags)
	b.uint16(h.Method)
	b.uint16(h.ModifiedTime)
	b.uint16(h.ModifiedDate)
	// In raw mode (caller does the compression), the values are either
	// written here or in the trailing data descriptor based on the header
	// flags.
	if h.raw && !h.hasDataDescriptor() {
		b.uint32(h.CRC32)
		b.uint32(uint32(min(h.CompressedSize64, uint32max)))

	}
	return paxHdrs, nil
}

// readHeader reads the next block header and assumes that the underlying reader
// is already aligned to a block boundary. It returns the raw block of the
// header in case further processing is required.
//
// The err will be set to io.EOF only when one of the following occurs:
//   - Exactly 0 bytes are read and EOF is hit.

	SRLW	X5, X6, X7				// bb535300
	SUBW	X5, X6, X7				// bb035340
	SRAW	X5, X6, X7				// bb535340
	ADDIW	$1, X6					// 1b031300
	SLLIW	$1, X6					// 1b131300
	SRLIW	$1, X6					// 1b531300
	SRAIW	$1, X6					// 1b531340
	ADDW	X5, X7					// bb835300
	SLLW	X5, X7					// bb935300
	SRLW	X5, X7					// bbd35300
	SUBW	X5, X7					// bb835340
	SRAW	X5, X7					// bbd35340
	ADDW	$1, X6					// 1b031300
	SLLW	$1, X6					// 1b131300