enteredAfter(phase.next) makes all subsequent enteredAfter(phase) become lost

[DarkDimius]

We have a miniphase

(new FirstTransform,
 new SyntheticMethods)

Both synthesize symbols an use enteredAfter to install them. If SyntheticMethods is first to clone the Scope in enteredAfter(SyntheticMethods) all subsequent updates to previous scopes do not get propagated: all enteredAfter(FirstTransform) will get lost.

I see 2 way to fix this: either make all phases run atGroupEnd(than they will always update the same scope) or enteredAfter needs to be updated to also install the Symbol to future Scopes.

@odersky, WDYT?

[DarkDimius]

I've tracked down some of the manifestations of #413 to this.

[DarkDimius]

The same applies to

(new LambdaLift,
           new Flatten,
           new RestoreScopes)

In the end a very strange mix of members in scopes is seen, as if future phase is first to enter a symbol, all symbol entered by past phases get lost.