Description:
------------
See test script.

This behavior change has been introduced in PHP7.2RC6, and can be fixed by the change on 710 of main/streams/streams.c:

```
-               if (!stream->wrapper || stream->wrapper->is_url) {
+               if (stream->wrapper != &php_plain_files_wrapper) {
```



Test script:
---------------
run on the shell:

php -r 'echo "ping"; stream_copy_to_stream(STDIN, STDOUT);' 


then type something to populate stdin, and hit "enter".
On "enter", the input should be copied to the STDOUT.
But on RC6, this doesn't happen until STDIN is closed.

Expected result:
----------------
see test script

Actual result:
--------------
see test script