Tests for static class proc, methods & iterators

This currently covers #2662 & #2710 bugs.

tests/metatype/ttypedesc3.nim

@@ -0,0 +1,19 @@
+import typetraits
+
+type
+  Base = object of RootObj
+  Child = object of Base
+
+proc pr(T: typedesc[Base]) = echo "proc " & T.name
+method me(T: typedesc[Base]) = echo "method " & T.name
+iterator it(T: typedesc[Base]) = yield "yield " & T.name
+
+Base.pr
+Child.pr
+
+Base.me
+when false:
+  Child.me #<- bug #2710
+
+for s in Base.it: echo s
+for s in Child.it: echo s #<- bug #2662