// matches build.Default.GOARCH.
					var archCandidates []*asmArch
					for _, fld := range strings.Fields(m[1]) {
						for _, a := range arches {
							if a.name == fld {
								archCandidates = append(archCandidates, a)
							}
						}
					}
					for _, a := range archCandidates {
						if a.name == build.Default.GOARCH {
							archCandidates = []*asmArch{a}
							break
						}
					}