run_tests.sh: don't change filenames to '<stdout>'.

run_tests.sh: don't change filenames to '<stdout>'.

Updated test. Used the following shell script to validate changes:

    #!/bin/bash

    for f2 in *.temp
    do
        f1=${f2%.temp}

        diff1=`diff $f1 $f2 | grep '^< ' | wc -l`
        diff1_fname=`diff $f1 $f2 | grep '^<\( #line [0-9]\+ "<stdout>"\|[ ]\+("<stdout>[^"]\+"\)' | wc -l`
        diff2=`diff $f1 $f2 | grep '^> ' | wc -l`
        diff2_fname=`diff $f1 $f2 | grep '^>\( #line [0-9]\+ "[^"]\+"\|[ ]\+("[^"]\+"\)' | wc -l`

        # missing: only changed filenames
        [ $diff1 -ne $diff1_fname ] && echo "FAIL1: $f1" && exit 1

        # added: only changed filenames
        [ $diff2 -ne $diff2_fname ] && echo "FAIL2: $f1" && exit 1

        # the number of missing changed filenames
        # equals to the number of added changed filenames
        [ $diff1_fname -ne $diff2_fname ] && echo "FAIL4: $f1" && exit 1
    done

    echo "OK"