It's not /really/ an infix operator, but it behaves like a very low
precedence prefix operator. On the other hand, 'try' and 'try!' can
freely move in and out of all the operations we add in fix-its, so
don't bother.
rdar://problem/22259867
Swift SVN r31200
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504