[Bug c++/94843] if i use pch and specify '-include' twice compilation fails

[m+gccbugs at gshep dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94843

--- Comment #1 from gccshep <m+gccbugs at gshep dot ru> ---
environment:

$ uname -a
Linux 5user6-7VirtualBox890 5.3.0-46-generic #38~18.04.1-Ubuntu SMP Tue Mar 31
04:17:56 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

tested with g++-8/9 :
$ g++-8 --version
g++-8 (Ubuntu 8.4.0-1ubuntu1~18.04) 8.4.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ g++-9 --version
g++-9 (Ubuntu 9.3.0-11ubuntu0~18.04.1) 9.3.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

It seems like it is reproducible with gcc too.

Also reproduced this with gcc/++ 5.5.0 on Slackware 64.