When a project uses PCH with explicit modules, the build will look like this:
- scan PCH dependencies
- explicitly build PCH
- scan TU dependencies
- explicitly build TU
Step 2 produces an object file for the PCH, which the dependency scanner needs to read in step 3. This patch adds support for this.
The clang-scan-deps invocation in the attached test would fail without this change.
Depends on D103516.