[Bug c/90476] prepossessor should error if #line 0

[jg at jguk dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90476

--- Comment #1 from Jonny Grant <jg at jguk dot org> ---
Created attachment 46357
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46357&action=edit
test case