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
Many individual LValue evaluations still reflect
broken semantics: for example, the index expression
in a subscript l-value is delayed until the l-value
is actually projected. But this is a necessary
step in the right direction.
Swift SVN r23532
Parse '_' as a DiscardAssignmentExpr. Type-check it as an lvalue, and check that it only appears in the LHS of AssignExprs. During matching pattern resolution, convert it into an AnyPattern. In SILGen, when we see '_' in the LHS of an assignment, ignore the corresponding RHS rvalue.
Swift SVN r8848
