swift234

Reapply r23982, which moves mandatory inlining after DI and inout deshadowing.
This fixes some serious DI problems where it would be broken with transparent
functions like ++.

Previously, this had to be reverted because we were relying on mandatory inlining
to inline closure-taking stdlib functions (like &&/||) before inout deshadowing
happened.  With mandatory inlining moved after inout deshadowing, we were getting
a lot of inout shadow temporaries around, which notably defeated important COW
optimizations by increasing refcounts in unpredictable ways.  

The new @__noescape attribute handles this for us now, because @__noescape closures
(like the autoclosure arguments to ||/&&) no longer block inout deshadowing.



Swift SVN r24142