[PATCH] Fix PR c++/66850 (Adding a forward declaration causes ICE on valid code)

[Patrick Palka]

On Sun, Jul 12, 2015 at 7:31 PM, Patrick Palka <patrick@parcs.ath.cx> wrote:
> This patch attempts resolve the mentioned PR by fixing two underlying
> issues:

I should note that there is some overlap between the fixes.
Technically fix #2 is sufficient to resolve the PR, whereas fix #1 can
only resolve the first test case in namespace X below.  But fix #1
seems to be sensible even if it is redundant.