[svn r124] Fixed another D vararg + return in ptr bug.

Fixed some nested function calls failed to resolve the context ptr.

test/bug77.d

@@ -0,0 +1,17 @@
+module bug77;
+import std.c.string;
+void main()
+{
+    size_t len;
+    void func2()
+    {
+        char* prefix = "";
+
+        void func()
+        {
+        len = strlen(prefix);
+        assert(len == 0);
+        }
+    }
+    func2();
+}