This reverts commit 83637aea6ea726f7fc4c17e56ac60c289e2d98db.

	[PATCH] Don't use non blocking pipes for RUBY_CRASH_REPORT

	[Bug #21703]

	RUBY_CRASH_REPORT does not work in some cases when shelling out on Linux.
	For example, given the following shell script dump.sh:

	    #!/usr/bin/env bash
	    cat > /tmp/crash

	And we see it fails like this:

	    $ RUBY_CRASH_REPORT="|dump.sh" ruby -rfiddle -e "Fiddle::Pointer.new(1, 10)[0]"
	    cat: -: Resource temporarily unavailable

	[PATCH] [Bug #21625] Allow io/wait methods with `IO#ungetc` in text mode

	Fix handling of `error`/`errno` in `io_internal_wait`. (#12961)

	[Bug #21195]

	Ensure IO.copy_stream buffer is an independent string

	Otherwise, changes to the buffer by the destination write method
	could result in data changing for supposedly independent strings.

	Fixes [Bug #21131]

	[Bug #20995] Protect `IO.popen` block from exiting by exception

	[Bug #20924] Fix reading with delimiter in wide character encodings

	[Bug #20787] Check the separator in `IO#readline` as well as 3.2

	Make io_fwrite safe for compaction

	[Bug #20169]

	Embedded strings are not safe for system calls without the GVL because
	compaction can cause pages to be locked causing the operation to fail
	with EFAULT. This commit changes io_fwrite to use rb_str_tmp_frozen_no_embed_acquire,
	which guarantees that the return string is not embedded.

Don't wait in `io_binwrite_string` if not necessary. (#9792)

	---
	 io.c | 8 +++-----
	 1 file changed, 3 insertions(+), 5 deletions(-)