Protocol associated types not visible via generics

IDE: Visual Studio X/Fire
Version: 10.0.0.2415 (develop)
Target (If relevant): OSX
Description:
Associated types of a protocol are, wrongly, not visible members of a generic constrained to the protocol.

Expected Behavior:
Compiles.
Actual Behavior:
see below.
Steps:

protocol P {
  associatedtype A
}

struct S<T: P> {
	typealias A = T.A // E28 Unknown type "T.A"
}

Thanks, logged as bugs://82831