These tests were relying on sourcekitd parsing as frontend instead of
using the driver. Update them now to avoid churn when we fix command
line argument parsing in sourcekit.
The changes from clang-importer-sdk to clang-importer-sdk-nosource -I %t
are because clang-importer-sdk implies using -enable-source-import.
Rather than hack them up to use -Xfrontend, it is cleaner to just stop
using source import at all for these tests. Incidentally, this improved
fidelity in a few places. When using the generated swift modules we
also need to pass a target triple to sourcekit, which exposed some tests
that had mac-specific data. This is a systemic issue for sourcekit
tests, but for now just make those few specific tests that we had
problems with run only on mac.
Cursor info requires access to the underlying AST, which is not
thread-safe. This manifest as crashes when performing concurrent
cursor-info requests on the same generated interface. We already
prevented concurrent cursor-infos on regular Swift files by using the
ASTManager, but generated interfaces use the InterfaceGenContext which
may use either an ASTUnit or its own internal CompilerInstance.
rdar://problem/27311624
