[Ada] Add Flush to Sequential_IO and Direct_IO.

[Arnaud Charlet]

This Flush routine is equivalent to the one found in the Text_IO
package for example.

The Flush procedure synchronizes the external file with the internal
file (by flushing any internal buffers) without closing the file.

Tested on x86_64-pc-linux-gnu, committed on trunk

2017-01-06  Pascal Obry  <obry@adacore.com>

	* a-direio.adb, a-direio.ads, a-sequio.adb, a-sequio.ads: Add Flush to
	Sequential_IO and Direct_IO.

-------------- next part --------------
Index: a-direio.adb
===================================================================
--- a-direio.adb	(revision 244124)
+++ a-direio.adb	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2012, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
 --                                                                          --
 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
 -- terms of the  GNU General Public License as published  by the Free Soft- --
@@ -108,6 +108,15 @@
       return DIO.End_Of_File (FP (File));
    end End_Of_File;
 
+   -----------
+   -- Flush --
+   -----------
+
+   procedure Flush (File : File_Type) is
+   begin
+      FIO.Flush (AP (File));
+   end Flush;
+
    ----------
    -- Form --
    ----------
Index: a-direio.ads
===================================================================
--- a-direio.ads	(revision 244124)
+++ a-direio.ads	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
 --                                                                          --
 -- This specification is derived from the Ada Reference Manual for use with --
 -- GNAT. The copyright notice above, and the license provisions that follow --
@@ -94,6 +94,8 @@
 
    function Is_Open (File : File_Type) return Boolean;
 
+   procedure Flush (File : File_Type);
+
    ---------------------------------
    -- Input and Output Operations --
    ---------------------------------
Index: a-sequio.adb
===================================================================
--- a-sequio.adb	(revision 244124)
+++ a-sequio.adb	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2013, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
 --                                                                          --
 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
 -- terms of the  GNU General Public License as published  by the Free Soft- --
@@ -121,6 +121,15 @@
       return FIO.End_Of_File (AP (File));
    end End_Of_File;
 
+   -----------
+   -- Flush --
+   -----------
+
+   procedure Flush (File : File_Type) is
+   begin
+      FIO.Flush (AP (File));
+   end Flush;
+
    ----------
    -- Form --
    ----------
Index: a-sequio.ads
===================================================================
--- a-sequio.ads	(revision 244124)
+++ a-sequio.ads	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
 --                                                                          --
 -- This specification is derived from the Ada Reference Manual for use with --
 -- GNAT. The copyright notice above, and the license provisions that follow --
@@ -90,6 +90,8 @@
 
    function Is_Open (File : File_Type) return Boolean;
 
+   procedure Flush (File : File_Type);
+
    ---------------------------------
    -- Input and output operations --
    ---------------------------------