Having semantic checking in type validation introduces the potential for more recursion, triggering crashes. By moving this semantic restriction out to a later stage, we make it more robust. Fixes 6 compiler crashers, although it regressed one compiler crasher that hits a different known issue (assertions in addGenericParameters when we have multiple parameters at the same depth).
Swift SVN r26226
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 can only occur when validating mutually recursive existentials in type reference expressions, so it's "safe" to avoid validating member value decls in this case. There are still potential holes in our mechanism for checking for unsupported existentials, but at least this will eliminate another common crasher. (Crash suite scenario 010.)
Swift SVN r22035
When trying to implement deduplication of results, found and fixed an issue
with loose checks for generic overload checking.
rdar://17995317
Swift SVN r21276
These changes prevent a certain class of bogus errors, as well as several crashers. Unfortunately, though, they don't quite get us to the point where we can broadly use recursively defined protocol requirements, in the standard library. (To do so would require significant changes across the entire stack.)
Swift SVN r19019
