Make std* blocking file-descriptors.

sdk/lib/io/stdio.dart

Index: sdk/lib/io/stdio.dart
diff --git a/sdk/lib/io/stdio.dart b/sdk/lib/io/stdio.dart
index 5c1fa8f734fa04146c3194a2744b3a468a0e7e67..5b5e62f539c7b0a669d7760ca83769441ac4ed4c 100644
--- a/sdk/lib/io/stdio.dart
+++ b/sdk/lib/io/stdio.dart
@@ -273,8 +273,12 @@ IOSink get stderr {
 StdioType stdioType(object) {
   if (object is _StdStream) {
     object = object._stream;
-  } else if (object is _StdSink) {
-    object = object._sink;
+  } else if (object == stdout || object == stderr) {
+    switch (_StdIOUtils._getStdioHandleType(object == stdout ? 1 : 2)) {
+      case _STDIO_HANDLE_TYPE_TERMINAL: return StdioType.TERMINAL;
+      case _STDIO_HANDLE_TYPE_PIPE: return StdioType.PIPE;
+      case _STDIO_HANDLE_TYPE_FILE:  return StdioType.FILE;
+    }
   }
   if (object is _FileStream) {
     return StdioType.FILE;
@@ -303,4 +307,5 @@ class _StdIOUtils {
   external static _getStdioOutputStream(int fd);
   external static Stdin _getStdioInputStream();
   external static int _socketType(nativeSocket);
+  external static _getStdioHandleType(int fd);
 }