stdlib: Fix handling of standard library types in _typeByName.

Mangling for the Swift module is 's', not 'Ss'.

Author: jckarter

stdlib/public/core/Misc.swift

@@ -104,7 +104,7 @@ func _typeByName(name: String) -> Any.Type? {
   // actually a class.
   var name = "C"
   if components[0] == "Swift" {
-    name += "Ss"
+    name += "s"
   } else {
     name += String(components[0].characters.count) + components[0]
   }

test/1_stdlib/Runtime.swift

@@ -318,6 +318,9 @@ Runtime.test("typeByName") {
   expectTrue(_typeByName("a.SomeSubclass") == SomeSubclass.self)
   // name lookup will be via protocol conformance table
   expectTrue(_typeByName("a.SomeConformingClass") == SomeConformingClass.self)
+  // FIXME: NonObjectiveCBase is slated to die, but I can't think of another
+  // nongeneric public class in the stdlib...
+  expectTrue(_typeByName("Swift.NonObjectiveCBase") == NonObjectiveCBase.self)
 }
 
 Runtime.test("demangleName") {