Unaligned store in `CaptureStructure.encode(to:)`

[rxwei]

https://gist.github.com/rjmccall/28fa7ff66402fddde4114970201f7da5

Reproducible with an asan build. (Thanks @rjmccall!)

    buffer.storeBytes(
      of: Self.currentSerializationVersion, as: SerializationVersion.self)

[stephentyrone]

First client for https://forums.swift.org/t/pitch-unaligned-loads-and-stores-from-raw-memory/55036?

[glessard]

My suggestion for now:

withUnsafeBytes(of: Self.currentSerializationVersion) {
   buffer.copyBytes(from: $0)
}