Autolinking was added to the frontend in 22912bc3b. It was disabled on
Linux in 198402dcf, and further constrained to be disabled on "linux-gnu"
in 83b4384fa. Since then, more flavors of Linux have become supported
by Swift: "linux-gnueabihf" in 4bf81e09d, and "freebsd" in f41b791d4.
Autolinking most likely does not work on any of these platforms, so
mark it as unsupported for now.
Other tests that only mark "linux-gnu" as unsupported do so for similar
reasons. Ensure unsupported tests for "linux-gnu" are also unsupported
on similar platforms.
The list of libraries to be loaded was not sorted in the topological
order of dependencies, and we don't know the dependencies in advance.
Now we try to load all libraries until we stop making progress.
rdar://19742274
Swift SVN r25069
