There is a followup fix for a unit test introduced at D102906. The test file was placed into a temp folder and test assumed that it would be visible without the full path specification.
This behaviour can be changed in future and it would be good to specify full path to the file at the test.
Test Plan:
```
ninja check-clang-tools
```
Reviewed By: DmitryPolukhin
Differential Revision: https://reviews.llvm.org/D104021
The diff adds Remark to Diagnostic::Level for clang tooling. That makes
Remark diagnostic level ready to use in clang-tidy checks: the
clang-diagnostic-module-import becomes visible as a part of the change.
Ivan Murashko