GDB/MI reporting non-ASCII file names

[Eli Zaretskii <eliz at gnu dot org>]

It seems that "gdb -i=mi" reports non-ASCII characters in filenames as
octal escapes.  Here's an example from a GNU/Linux system whose
locale's codeset is UTF-8:

  (gdb)
  -file-list-exec-source-file
  ^done,line="1",file="/home/e/eliz/\320\277\321\200\320\276\320\262\320\265\321\200\320\272\320\260.c",fullname="/srv/data/home/e/eliz/\320\277\321\200\320\276\320\262\320\265\321\200\320\272\320\260.c",macro-info="1"

Each of these \nnn is a string of literal ASCII characters, not a
single byte whose octal value is nnn.  Why does MI do this?  Where in
GDB do we convert bytes into this representation, and is there any way
of asking MI not to make these conversions?

The reason for these questions is that Emacs's GDB interface fails to
recognize the original file name that hides behind these escapes, and
the result is that debugging a program whose source file names include
non-ASCII characters fails to display the source files through which
GDB steps.

It is, of course, possible to decode these escapes on Emacs's side.
But since many MI output records include file-name fields, doing so
everywhere is quite a PITA.  So if there's a way to avoid the need for
decoding in the first place, it's preferable.

TIA