Decide which files we should re-index when the package is changed #1251
Description
When the build system is modified, we need to do two things:
- Index all new files
- For all other files, we have three options:
- Trigger a re-index for them (most correct)
- Diff build settings for the files and only re-index if build settings have changed (slightly correct but might miss indexing changes if a new file changes overload resolution without build settings changing)
- Assume that the updated package doesn’t affect the index and don’t re-index
rdar://127476161