[Ada] Read directory in Ada.Directories.Start_Search rather than Get_Next_Entry
gcc/ada/
* libgnat/a-direct.adb (Search_Data): Remove type.
(Directory_Vectors): New package instantiation.
(Search_State): New type.
(Fetch_Next_Entry): Remove.
(Close): Remove.
(Finalize): Rewritten.
(Full_Name): Ditto.
(Get_Next_Entry): Return next entry from Search results vector
rather than querying the directory directly using readdir.
(Kind): Rewritten.
(Modification_Time): Rewritten.
(More_Entries): Use Search state cursor to determine if more
entries are available for users to read.
(Simple_Name): Rewritten.
(Size): Rewritten.
(Start_Search_Internal): Rewritten to load the contents of the
directory that matches the pattern and filter into the search
object.
* libgnat/a-direct.ads (Search_Type): New type.
(Search_Ptr): Ditto.
(Directory_Entry_Type): Rewritten to support new Start_Search
procedure.
* libgnat/s-filatt.ads (File_Length_Attr): New function.