armv7k can return 16-byte structs in registers, but the Swift side of
the reflection implementation assumes these structs return in memory.
Adding an intermediating struct for return values with an empty user
destructor guarantees that they come back in memory.
rdar://21215339
Swift SVN r29274
the value buffer comes first.
The motivation for doing this is similar to the
motivation for moving it for class existentials:
it eliminates the need for an offset for the most
common accesses, which is particularly important
for the generic value witnesses.
Also try to hard-code that layout in fewer places,
or at least static_assert the places that have to
do so.
Swift SVN r16279
A useful unsafe optimization for potential implementations of Mirror that have existing heap storage to share from the value, like for Array or Dictionary.
Swift SVN r14186
Define a "Mirror" protocol with methods for querying the number of children a structured value has, getting the name and mirror for each of those children, and a string and "IDE representation" of the value, as needed by playgrounds and by our planned generic printing facility.
In the runtime, define a "reflect" function that can provide a Mirror for any object, either using a "Reflectable" protocol conformance if available, or falling back to a magic implementation in the runtime that grovels the type metadata. Stub out a bare minimum default implementation.
Swift SVN r14139
