[gcc r10-11071] doc: Document correct -fwide-exec-charset defaults [PR41041]

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:87b0935ed43d971a6eeebca963fb673628f138dd

commit r10-11071-g87b0935ed43d971a6eeebca963fb673628f138dd
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Nov 4 12:10:32 2022 +0000

    doc: Document correct -fwide-exec-charset defaults [PR41041]
    
    As shown in the PR, the default is not UTF-32 but rather UTF-32BE or
    UTF-32LE, avoiding the need for a byte order mark in literals.
    
    gcc/ChangeLog:
    
            PR c/41041
            * doc/cppopts.texi: Document -fwide-exec-charset defaults
            correctly.
    
    (cherry picked from commit e50ea3a42f058c14ee29327d5277ab0435e3d36b)

Diff:
---
 gcc/doc/cppopts.texi | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/gcc/doc/cppopts.texi b/gcc/doc/cppopts.texi
index 7f1849d841f..b02c26638ea 100644
--- a/gcc/doc/cppopts.texi
+++ b/gcc/doc/cppopts.texi
@@ -314,9 +314,10 @@ supported by the system's @code{iconv} library routine.
 @opindex fwide-exec-charset
 @cindex character set, wide execution
 Set the wide execution character set, used for wide string and
-character constants.  The default is UTF-32 or UTF-16, whichever
-corresponds to the width of @code{wchar_t}.  As with
-@option{-fexec-charset}, @var{charset} can be any encoding supported
+character constants.  The default is one of UTF-32BE, UTF-32LE, UTF-16BE,
+or UTF-16LE, whichever corresponds to the width of @code{wchar_t} and the
+big-endian or little-endian byte order being used for code generation.  As
+with @option{-fexec-charset}, @var{charset} can be any encoding supported
 by the system's @code{iconv} library routine; however, you will have
 problems with encodings that do not fit exactly in @code{wchar_t}.