generated output.
	-gccgo
		Generate output for the gccgo compiler rather than the
		gc compiler.
	-gccgoprefix prefix
		The -fgo-prefix option to be used with gccgo.
	-gccgopkgpath path
		The -fgo-pkgpath option to be used with gccgo.
	-gccgo_define_cgoincomplete
		Define cgo.Incomplete locally rather than importing it from
		the "runtime/cgo" package. Used for old gccgo versions.
	-godefs

// zero value of sparseHoles logically represents a normal file (i.e., there are
// 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:
//

are predefined and refer to registers.
The exact set depends on the architecture.
</p>

<p>
There are four predeclared symbols that refer to pseudo-registers.
These are not real registers, but rather virtual registers maintained by
the toolchain, such as a frame pointer.
The set of pseudo-registers is the same for all architectures:
</p>

<ul>

<li>
<code>FP</code>: Frame pointer: arguments and locals.

	type span struct {
		start int
		end   int
	}
	spans := make([]span, 0, 32)

	// Find the field start and end indices.
	// Doing this in a separate pass (rather than slicing the string s
	// and collecting the result substrings right away) is significantly
	// more efficient, possibly due to cache effects.
	start := -1 // valid span start if >= 0
	for i := 0; i < len(s); {