Control characters in declare output

[Rob Foehl]

Prompted (pun intended) by the recent thread on detecting missing newlines 
in command output, I'd had another look at my own version, and discovered 
a potential issue with control characters being written as-is in declare 
output.  Minimal (harmless) reproducer:

╶➤ x () { echo $'\e[31m'"oops"$'\e[0m'; }

╶➤ declare -f x
x ()
{
    echo ''"oops"''
}

Emits the string in red in a terminal.  Any instances with control 
sequences that do anything more invasive with the terminal cause more 
trouble.

Similarly:

╶➤ y=$'\e[31m'"oops"$'\e[0m'

╶➤ declare -p y
declare -- y="oops"

String again in red.  Compare with:

╶➤ set |grep ^y=
y=$'\E[31moops\E[0m'

No issues with the set output.  As they can both be usefully re-read by 
the shell, is there any possibility for similarly escaped output from the 
declare builtin, instead of raw control characters?

-Rob