CTypes: make typealiases public

Explicitly mark the `CChar` and `CInt` `typealias`es `public` as they are meant to be available to users of the standard library.

Author: compnerd

Sources/Core/CTypes.swift

@@ -2,6 +2,6 @@
 // All Rights Reserved.
 // SPDX-License-Identifier: BSD-3
 
-typealias CChar = Int8
+public typealias CChar = Int8
 
-typealias CInt = Int32
+public typealias CInt = Int32