LLVM r336847 changed FileCheck's CHECK-DAG feature to stop supporting
overlapping matches. I already fixed one test by invoking FileCheck with the
-allow-deprecated-dag-overlap option, but it turns out there are a bunch
more of them. This change applies the same workaround to all of them.
* A bunch of them require objc_interop because they import code containing
Objective-C.
* Many others fail on Ubuntu 14.04 because the C++ there doesn't have a
functional std::regex implementation which is required by the
`complete-test` tool.
It may be possible to adjust some of these tests in the future to not
need these extra requirements, but this is a straightforward way to
clean up Linux test results for now.
The code goes into its own sub-tree under 'tools' but tests go under 'test',
so that running 'check-swift' will also run all the SourceKit tests.
SourceKit is disabled on non-darwin platforms.
