size    uintptr             // length of entries array. Always a power of 2.
	count   uintptr             // current number of filled entries.
	entries [itabInitSize]*itab // really [size] large
}

func itabHashFunc(inter *interfacetype, typ *_type) uintptr {
	// compiler has provided some good hash codes for us.
	return uintptr(inter.Type.Hash ^ typ.Hash)
}

// getitab should be an internal detail,

			"alignUp",
			"bucketMask",
			"bucketShift",
			"chanbuf",
			"evacuated",
			"fastlog2",
			"float64bits",
			"funcspdelta",
			"getm",
			"getMCache",
			"isDirectIface",
			"itabHashFunc",
			"nextslicecap",
			"noescape",
			"pcvalueCacheKey",
			"rand32",
			"readUnaligned32",
			"readUnaligned64",
			"releasem",
			"roundupsize",
			"stackmapdata",
			"stringStructOf",