if !ok || failed {
		t.Errorf("asm: %s assembly failed", goarch)
		return
	}
	output := strings.Split(testOut.String(), "\n")

	// Reconstruct expected output by independently "parsing" the input.
	data, err := os.ReadFile(input)
	if err != nil {
		t.Error(err)
		return
	}
	lineno := 0
	seq := 0
	hexByLine := map[string]string{}
	lines := strings.SplitAfter(string(data), "\n")
Diff:
	for _, line := range lines {

					}
				default:
					t.Fatalf("test %d, unknown test operation: %T", i, tf)
				}
			}

			if v.file != "" {
				want, err := os.ReadFile(v.file)
				if err != nil {
					t.Fatalf("ReadFile() = %v, want nil", err)
				}
				got := buf.Bytes()
				if !bytes.Equal(want, got) {
					t.Fatalf("incorrect result: (-got +want)\n%v", bytediff(got, want))
				}
			}
		})

	"os.FileInfo", "fs.FileInfo",
	"os.FileMode", "fs.FileMode",
	"os.PathError", "fs.PathError",
)

func fileFeatures(filename string, needApproval bool) []string {
	bs, err := os.ReadFile(filename)
	if err != nil {
		log.Fatal(err)
	}
	s := string(bs)

	// Diagnose common mistakes people make,
	// since there is no apifmt to format these files.

	MRS	ICC_EOIR0_EL1, R5                                // ERROR "system register is not readable"
	MRS	ICC_DIR_EL1, R5                                  // ERROR "system register is not readable"
	MRS	ICC_ASGI1R_EL1, R5                               // ERROR "system register is not readable"
	MRS	ICV_EOIR0_EL1, R3                                // ERROR "system register is not readable"