This may not be how we want to implement class equality checks in the
long run, but in the short term this is _very_ handy. See also:
<rdar://problem/12939898> ER: formalize root classes
This also removes support for greater-than/less-than on Vectors, which
makes no sense given that this has everything to do with the randomness
of the memory allocator and nothing intrinsic about Vectors or class
references in general.
Swift SVN r3628
1) Move the low-level runtime code into swift/runtime
2) Move the high-level "standard library" code into swift/stdlib
The key difference is that the 'runtime' contains language support logic
(like retain/release logic) that the compiler assumes to always exist
and may assume intimate details about the implementation. This library
will have intimate knowledge of the swift ABI.
In contrast, the 'stdlib' can be completely rewritten and the
language/compiler make little if any assumptions about it. It is
expected to reexport fundamental types and operators, and implement
fundamental policies (precedence, implicit conversions, etc).
Swift SVN r3045
