Backport 037e8112b97 for the 10.x branch

Greetings Joel, all,

I'd like to nominate a patch for the 10.x branch, in particular
037e8112b97 ("[gdb/server] Don't overwrite fs/gs_base with -m32").
Since I just missed 10.2 - it would be great if we can have it in the
next bugfix release.

As the commit suggests, without the fix gdbserver is virtually
unusable for any 32bit application.

Thanks in advance and apologies if this isn't the correct format for
such a request.
-Emil

[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff_plain;h=037e8112b9794a633248e5aa5943f3be273e0a20