swift234

Now that allocbox-to-stack is run before DI, we can run inout-deshadow
before DI.  This will enable us to simplify its algorithm to make it 
more predictable and powerful.

To test the end-to-end behavior of inout promotion in the compiler,
I'm adding a new integration test with some examples that we cover 
today.  There is still more work to be done though.



Swift SVN r9748