Enable use of /proc/self/cmdline on Solaris as well as Linux, now that we have
support for it via PSARC/2015/207, instead of falling through to no-op case in
shell_global_reexec_self().

Submitted upstream: https://bugzilla.gnome.org/show_bug.cgi?id=776199
Accepted for 3.24 release cycle:
https://git.gnome.org/browse/gnome-shell/commit/?id=ddfdfaed785e9ef4291a2bd921009a79191ff760

diff --git a/src/shell-global.c b/src/shell-global.c
index 6dda352..a698f0e 100644
--- a/src/shell-global.c
+++ b/src/shell-global.c
@@ -1244,7 +1244,7 @@ shell_global_reexec_self (ShellGlobal *global)
   GPtrArray *arr;
   gsize len;
 
-#if defined __linux__
+#if defined __linux__ || defined __sun
   char *buf;
   char *buf_p;
   char *buf_end;