[clang] [clang] Invert condition refactored in #160935 (PR #161583)

[Jan Svoboda via cfe-commits]

jansvoboda11 wrote:

Looking at the code, this condition should kick in when `BeginLoc` is preceded by a `#line` that points to a file that doesn't exist - in that case we ask for the source location again, now ignoring that directive (i.e. resolving to the file the `BeginLoc` physically appears in). I agree more test coverage would be nice here, but I don't have more time to invest into chasing that.

https://github.com/llvm/llvm-project/pull/161583