[dart:io] Don't close stdin with a socket finalizer

runtime/bin/file_macos.cc

Index: runtime/bin/file_macos.cc
diff --git a/runtime/bin/file_macos.cc b/runtime/bin/file_macos.cc
index 9f09b7932a21d9b74fae2a63702dd10afefab901..0c8d9d61c2ca7b9056124d9d96644065b8f962ee 100644
--- a/runtime/bin/file_macos.cc
+++ b/runtime/bin/file_macos.cc
@@ -540,10 +540,7 @@ File::StdioHandleType File::GetStdioHandleType(int fd) {
   struct stat buf;
   int result = fstat(fd, &buf);
   if (result == -1) {
-    const int kBufferSize = 1024;
-    char error_message[kBufferSize];
-    Utils::StrError(errno, error_message, kBufferSize);
-    FATAL2("Failed stat on file descriptor %d: %s", fd, error_message);
+    return kOther;
   }
   if (S_ISCHR(buf.st_mode)) {
     return kTerminal;