Remove stray character.

Author: adrian-prantl

include/swift/Strings.h

@@ -113,7 +113,7 @@ constexpr static BuiltinNameStringLiteral BUILTIN_TYPE_NAME_UNSAFEVALUEBUFFER =
     {"Builtin.UnsafeValueBuffer"};
 /// The name of the Builtin type for UnknownObject
 ///
-/// This no longer exists as an AST-accessible type, but it's still used for 
+/// This no longer exists as an AST-accessible type, but it's still used for
 /// fields shaped like AnyObject when ObjC interop is enabled.
 constexpr static BuiltinNameStringLiteral BUILTIN_TYPE_NAME_UNKNOWNOBJECT = {
     "Builtin.UnknownObject"};