'Ss' appears in manglings tens of thousands of times in the standard library and is also incredibly frequent in other modules. This alone is enough to shrink the standard library by 59KB.
Swift SVN r32409
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
This is to work around a bug on the unchecked optimized stdlib builder which due
to a problem in the cmake build chain runs the checks enabled version of this
test. This commit makes sure that the test will not run until this is resolved.
Swift SVN r23074