added missing test files

tests/metatype/twildtypedesc.nim

@@ -0,0 +1,43 @@
+discard """
+  output: '''123
+123
+123
+123
+123
+123'''
+"""
+
+import strutils
+
+proc unpack(t: typedesc[string], v: string): string = $v
+proc unpack(t: typedesc[int], v: string): int = parseInt(v)
+
+proc unpack[T](v: string): T =
+  unpack T, v
+
+var s = "123"
+
+assert(unpack[string](s) is string)
+assert(unpack[int](s) is int)
+
+echo unpack[int](s)
+echo unpack[string](s)
+
+echo unpack(int,s)
+echo unpack(string,s)
+
+template `as`*(x: untyped, t: typedesc): untyped = unpack(t,x)
+
+echo s as int
+echo s as string
+
+# bug #4534
+
+proc unit(t: typedesc[int]): t = 0
+proc unit(t: typedesc[string]): t = ""
+proc unit(t: typedesc[float]): t = 0.0
+
+assert unit(int) == 0
+assert unit(string) == ""
+assert unit(float) == 0.0
+