func structfieldSize(arch *sys.Arch) int { return abi.StructFieldSize(arch.PtrSize) } // runtime.structfield
func uncommonSize(arch *sys.Arch) int    { return int(abi.UncommonSize()) }           // runtime.uncommontype

// Type.commonType.kind
func decodetypeKind(arch *sys.Arch, p []byte) abi.Kind {
	return abi.Kind(p[2*arch.PtrSize+7]) & abi.KindMask //  0x13 / 0x1f
}