Change stdout/stderr to binary mode on Windows

Every other file opened in Windows is in binary mode, and there is no
way of opening a file in text mode.

This is a breaking change if one is relying on the CR insertion
when writing to stdout/stderr on Windows.

BUG=#19334
R=kustermann@google.com

Review URL: https://codereview.chromium.org//1228053002.

runtime/bin/file_win.cc

@@ -196,6 +196,7 @@ File* File::OpenStdio(int fd) {
     default:
       UNREACHABLE();
   }
+  _setmode(fd, _O_BINARY);
   return new File(new FileHandle(fd));
 }
 

tests/standalone/io/stdio_nonblocking_test.dart

@@ -17,12 +17,7 @@ void main() {
                   print(result.stdout);
                   print(result.stderr);
     Expect.equals(1, result.exitCode);
-    if (Platform.isWindows) {
-      Expect.equals('stdout\r\n\r\ntuodts\r\nABCDEFGHIJKLM\r\n', result.stdout);
-      Expect.equals('stderr\r\n\r\nrredts\r\nABCDEFGHIJKLM\r\n', result.stderr);
-    } else {
-      Expect.equals('stdout\n\ntuodts\nABCDEFGHIJKLM\n', result.stdout);
-      Expect.equals('stderr\n\nrredts\nABCDEFGHIJKLM\n', result.stderr);
-    }
+    Expect.equals('stdout\n\ntuodts\nABCDEFGHIJKLM\n', result.stdout);
+    Expect.equals('stderr\n\nrredts\nABCDEFGHIJKLM\n', result.stderr);
   });
 }