Fix a number of issues with determining the type of stdio

tests/standalone/io/dart_std_io_pipe_test.sh

Index: tests/standalone/io/dart_std_io_pipe_test.sh
diff --git a/tests/standalone/io/dart_std_io_pipe_test.sh b/tests/standalone/io/dart_std_io_pipe_test.sh
index 9677dc7d4473866ea0a0cd9e11892e57d8773b39..7caa1edabe481a4953493d95dcc6c0aeba47f7f1 100755
--- a/tests/standalone/io/dart_std_io_pipe_test.sh
+++ b/tests/standalone/io/dart_std_io_pipe_test.sh
@@ -6,8 +6,12 @@
 # $3: Argument to dart echoing script (0, 1 or 2)
 # $4: File for output from piping stdout and stderr
 # $5: File prefix for output from redirecting stdout and stderr to a file.
+# $6: Stdio type of stdin
 
 # Test piping and stdio file redirection.
-echo "Hello" | $1 $2 $3 2>&1 | cat - > $4
-$1 $2 $3 < $4 > $5.stdout 2> $5.stderr
-$1 $2 $3 < $4 >> $5.stdout 2>> $5.stderr
+echo "Hello" | $1 $2 $3 pipe pipe pipe 2>&1 | cat - > $4
+$1 $2 $3 $6 file file < $4 > $5.stdout 2> $5.stderr
+$1 $2 $3 $6 file file < $4 >> $5.stdout 2>> $5.stderr
+$1 $2 $3 $6 terminal terminal < $4 > /dev/null 2> /dev/null
+$1 $2 $3 $6 terminal pipe < $4 2>&1 > /dev/null
+$1 $2 $3 $6 terminal terminal < $4 > /dev/null 2>&1