Fuchsia: Partial implementation of dart:io sockets

runtime/bin/fdutils_linux.cc

Index: runtime/bin/fdutils_linux.cc
diff --git a/runtime/bin/fdutils_linux.cc b/runtime/bin/fdutils_linux.cc
index 5a174ee151ca4dbb33754f7c98faabc96c4f91aa..7f4598bcc793b900b25f9b3f33a2bf067069f5b0 100644
--- a/runtime/bin/fdutils_linux.cc
+++ b/runtime/bin/fdutils_linux.cc
@@ -137,6 +137,13 @@ ssize_t FDUtils::WriteToBlocking(int fd, const void* buffer, size_t count) {
   return count;
 }
 
+
+void FDUtils::SaveErrorAndClose(intptr_t fd) {
+  int err = errno;
+  VOID_TEMP_FAILURE_RETRY(close(fd));
+  errno = err;
+}
+
 }  // namespace bin
 }  // namespace dart