Proposed resolution:

This wording is relative to N4562.

1. Edit [optional.optional]/p1 as follows::

   […] The contained value shall be allocated in a region of the optional<T> storage suitably aligned for the type T. It is implementation-defined whether over-aligned types are supported (C++14 §3.11). When an object of type optional<T> is contextually converted to bool, the conversion returns true if the object contains a value; otherwise the conversion returns false.

Addresses: fund.ts.v2

[optional.optional] does not specify whether over-aligned types are supported. In other places where we specify allocation of user-supplied types, we state that "It is implementation-defined whether over-aligned types are supported (3.11)." (Examples: [expr.new]/p1, [allocator.members]/p5, [temporary.buffer]/p1). We should presumably do the same thing here.