swift234

Add a destructor memory effect analysis

This adds an analysis to the compiler that identifies types that are may store
to memory on destruction.

It adds a compiler known protocol _DestructorSafeContainer that allows the
standard library to identify containers whose destructor's memory effects
depends strictly on the type parameters of the container.

Array<T> : _DestructorSafeContainer {} may not store to memory during
destruction if the bound T is a type that does not store to memory on
destruction.

This is needed to deduce that for example Array<Array<Int>> is does not store to
memory on destruction (e.g during a call to release).

rdar://18940376

Swift SVN r23242