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
We require some level of consistency between the way the overlays were
built and what we work with in our mock SDK. The IDE/sdk_sugar.swift
test failure was because the overlay referenced "init(coder:)" while
the test was looking for "init(withCoder:)". Hilarity ensued
<rdar://problem/17791048>.
This only impacts testing.
Swift SVN r20564