linux-user: Show heap address in /proc/pid/maps

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/syscall.c

@@ -8125,6 +8125,8 @@ static void open_self_maps_4(const struct open_self_maps_data *d,
 
     if (test_stack(start, end, info->stack_limit)) {
         path = "[stack]";
+    } else if (start == info->brk) {
+        path = "[heap]";
     }
 
     /* Except null device (MAP_ANON), adjust offset for this fragment. */