fixes endless recursion with static type parameters

tests/metatype/tstaticvector.nim

@@ -0,0 +1,17 @@
+
+type
+  RectArray*[R, C: static[int], T] = distinct array[R * C, T]
+   
+  StaticMatrix*[R, C: static[int], T] = object
+    elements*: RectArray[R, C, T]
+   
+  StaticVector*[N: static[int], T] = StaticMatrix[N, 1, T]
+ 
+proc foo*[N, T](a: StaticVector[N, T]): T = 0.T
+proc foobar*[N, T](a, b: StaticVector[N, T]): T = 0.T
+ 
+ 
+var a: StaticVector[3, int]
+ 
+echo foo(a) # OK
+echo foobar(a, a) # <--- hangs compiler