swift234

IRGen: Store non-bitwise-takable types out of line in existential containers.

Give non-bitwise-takable types the Allocate FixedPacking kind so that they get allocated out of line in fixed buffers. Small value types with @weak references seem rare enough to me that it's overall better to let existential containers be bitwise-takable than to pessimize their take operations for the few value types that aren't bitwise-takable.

While we're here, add an assertion to FixedTypeInfo::initializeWithTake to ensure that all non-bitwise-takable types override the default implementation.

Swift SVN r17008