https://github.com/qiongsiwu approved this pull request.
Thanks! LGTM.
There are two places where we reset file manager but do not reset the VFS.
Could you help me confirm that these are OK? I think they are because these are
already in frontend actions and I assume we intend to preserve the
qiongsiwu wrote:
I am seeing a trio of methods more or less called together often, but sometimes
one is omitted.
```
CompilerInstance::setVirtualFileSystem
CompilerInstance::setFileManager
CompilerInstance::setSourceManager // This is sometimes omitted.
```
In what cases do we want freedom to s
