Improve Interfaces.C.Generic_Strings
Fix the allocation sizes of Ada.Directories.Volumes in Windows
Reorder the local declarations of Ada.Directories.Information.Read_Symbolic_Link in Darwin
Add (or rename from Convert to) To_C into System.Zero_Terminated_Strings and Zero_Terminated_WStrings, use them, and use neither .all'Address nor ranged subtypes in for X'Address use clauses