Added test case

Previously offending code

tests/cpp/ttemplatetype.nim

@@ -0,0 +1,9 @@
+type
+  Map {.importcpp: "std::map", header: "<map>".} [T,U] = object
+
+proc cInitMap(T: typedesc, U: typedesc): Map[T,U] {.importcpp: "std::map<'*1,'*2>()", nodecl.}
+
+proc initMap[T, U](): Map[T, U] =
+  result = cInitMap(T, U)
+
+var x: Map[cstring, cint] = initMap[cstring, cint]()