implemented some functions h2-io-file.

renamed h2-sysapi to h2-os

h2/lib/h2-os.adb

@@ -0,0 +1,15 @@
+package body H2.OS is
+
+	package body File is separate;
+
+	procedure Set_File_Flag_Bits (Flag: in out File_Flag_Record; Bits: in File_Flag_Bits) is
+	begin
+		Flag.Bits := Flag.Bits or Bits;
+	end Set_File_Flag_Bits;
+
+	procedure Clear_File_Flag_Bits (Flag: in out File_Flag_Record; Bits: in File_Flag_Bits) is
+	begin
+		Flag.Bits := Flag.Bits and not Bits;
+	end Clear_File_Flag_Bits;
+
+end H2.OS;