Describe the bug
stderr doesn't print its input as a raw string but as an escaped json string.

To Reproduce

jq -n '"line1\nline2" | stderr | empty'

Outputs "line1\nline2"

Expected behavior
As the manual states:

stderr
Prints its input in raw and compact mode to stderr with no additional decoration, not even a newline.

I expected the program to output be:

line1
line2

Environment (please complete the following information):

• OS and Version: Redhat Enterprise Linux 6
• jq version 1.6