Add Windows support.

lib/src/util/io.dart

Index: lib/src/util/io.dart
diff --git a/lib/src/util/io.dart b/lib/src/util/io.dart
index cb35ed7c25a302d53e08aaa633f7b6fa60b27520..dbe34f4e01ff7965590232a7a83c39c58b672b53 100644
--- a/lib/src/util/io.dart
+++ b/lib/src/util/io.dart
@@ -14,6 +14,12 @@ import 'package:pub_semver/pub_semver.dart';
 import '../backend/operating_system.dart';
 import '../runner/application_exception.dart';
 
+/// The ASCII code for a newline character.
+const _newline = 0xA;
+
+/// The ASCII code for a carriage return character.
+const _carriageReturn = 0xD;
+
 /// The root directory of the Dart SDK.
 final String sdkDir =
     p.dirname(p.dirname(Platform.executable));
@@ -95,6 +101,30 @@ Future withTempDir(Future fn(String path)) {
   });
 }
 
+/// Return a transformation of [input] with all null bytes removed.
+///
+/// This works around the combination of issue 23295 and 22667 by removing null
+/// bytes. This workaround can be removed when either of those are fixed in the
+/// oldest supported SDK.
+///
+/// It also somewhat works around issue 23303 by removing any carriage returns
+/// that are followed by newlines, to ensure that carriage returns aren't
+/// doubled up in the output. This can be removed when the issue is fixed in the
+/// oldest supported SDk.
+Stream<List<int>> santizeForWindows(Stream<List<int>> input) {
+  if (!Platform.isWindows) return input;
+
+  return input.map((list) {
+    var previous;
+    return list.reversed.where((byte) {
+      if (byte == 0) return false;
+      if (byte == _carriageReturn && previous == _newline) return false;
+      previous = byte;
+      return true;
+    }).toList().reversed.toList();
+  });
+}
+
 /// Creates a URL string for [address]:[port].
 ///
 /// Handles properly formatting IPv6 addresses.