[clang] [Coverage] Fix assertion failure when a -isystem header invokes a user macro (PR #195427)

[Fangrui Song via cfe-commits]

MaskRay wrote:

> Thanks. This works. Sorry for the delay.
> 
> You may merge this. I know the deadline toward 22.1.7 is approaching. Then I will write excuses to the preceding request #181319.
> 
> I have confirmed both #181319 and this satisfies both testcases each other.
> 
> Could you close your #195422 as duplicate? I would be happy if we could respect the preceding reporter #179316.
> 
> I didn't notice this issue since I was running my testcases with -Asserts.

No problem! Thanks for identifying #179316 as the initial report. Closed #195422 as a duplicate.

https://github.com/llvm/llvm-project/pull/195427