swift234

Import C enumerations into usable struct types in Swift.

Import C enumeration types as either structs wrapping the underlying
integral type (when the C enumeration type has a name) or as the
underlying integral type (when the C enumeration type has no
name). The structs have a constructor from the underlying integral
type, so one can write, e.g., NSStringCompareOptions(0) to get a
zero-valued enumeration.

Enumerators are imported as a global read-only properties.

Once oneofs start to work, we'll have a way to map some enumeration
types to oneofs, either via a Clang attribute or by sniffing out
NS_ENUM (most likely both).

Once we have static data members of structs working, we'll replace the
global constants with prefix-stripped static variables within the
struct, so we can use ".foo" notation with them.

Once we have constant declarations, we'll map to those instead of
properties.

We can add |, &, and ~ operations are part of
<rdar://problem/13028799> and have not yet been implemented.

Fixes <rdar://problem/13028891>.


Swift SVN r3945