Validating the argument type might validate the enum decl in malformed (or
maybe even some valid?) code. We would call computeTwice() in this case,
leading to a crash.
Also clean up some test cases.
Swift SVN r30673
This allows @objc enum error types produced in Objective-C (e.g., via
+[NSError errorWithDomain:code:userInfo:]) to be bridged back to their
original enum types in Swift via pattern matching/catch blocks.
This finishes rdar://problem/20577517.
Swift SVN r28803
For @objc enums, raw values determine the representation values, so we have
to compute them eagerly in order for switch statements to work. Similarly,
if the enum is broken, we have to /fail/ eagerly so that we don't fall down
later on in IRGen.
rdar://problem/19775284
Swift SVN r25282
