[Bug preprocessor/60723] Line directives with incorrect system header flag

[dodji at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60723

--- Comment #12 from Dodji Seketeli <dodji at gcc dot gnu.org> ---
Created attachment 33010
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33010&action=edit
A patch candidate that I am currently testing

This the patch I am running through bootstrap at the moment.

The patch basically makes the pre-processor detects changes in system-ness of
tokens and upon each of these change, emits a line marking directive so that
the information about the system-ness change is not lost.

I haven't commented the code yet.

Nicholas, maybe you could test the patch and give me feedback until my (slow)
machine completes the bootstrap?

Thanks.