Recognize identical scope of nested structs

[dlangBugzillaToGithub]

Vladimir Panteleev (@CyberShadow) reported this on 2014-02-19T19:58:17Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=12208

Description

Currently, this code doesn't compile, although I think it should:

//////////////////////////////
struct S1(alias a)
{
	struct S2(alias b)
	{
		void foo()
		{
			a = b;
		}
	}
}

struct Test
{
	int i, j;
	S1!i.S2!j s;
}
//////////////////////////////