[Ada] Allow multiple units per file in GNATprove

For analysis tools that rely on information generated in ALI files, but
do not generate object files, the frontend did not generate the special
extension names like file~2.ali for unit 2 in the file. This is needed
to be able to analyze files with multiple units. Now fixed.

There is no impact on compilation.

2019-07-10  Yannick Moy  <moy@adacore.com>

gcc/ada/

	* osint-c.adb (Set_File_Name): Always add extension for multiple
	units per file mode.

From-SVN: r273339

gcc/ada/ChangeLog

+2019-07-10  Yannick Moy  <moy@adacore.com>
+
+	* osint-c.adb (Set_File_Name): Always add extension for multiple
+	units per file mode.
+
 2019-07-10  Corentin Gay  <gay@adacore.com>
 
 	* sysdep.c: Put include directive for 'vxWorks.h' before any

gcc/ada/osint-c.adb

@@ -385,18 +385,8 @@ package body Osint.C is
          end if;
       end loop;
 
-      --  Make sure that the output file name matches the source file name.
-      --  To compare them, remove file name directories and extensions.
-
-      if Output_Object_File_Name /= null then
-
-         --  Make sure there is a dot at Dot_Index. This may not be the case
-         --  if the source file name has no extension.
-
-         Name_Buffer (Dot_Index) := '.';
-
-         --  If we are in multiple unit per file mode, then add ~nnn
-         --  extension to the name before doing the comparison.
+      --  If we are in multiple-units-per-file mode, then add a ~nnn extension
+      --  to the name.
 
       if Multiple_Unit_Index /= 0 then
          declare
@@ -410,6 +400,16 @@ package body Osint.C is
          end;
       end if;
 
+      --  Make sure that the output file name matches the source file name.
+      --  To compare them, remove file name directories and extensions.
+
+      if Output_Object_File_Name /= null then
+
+         --  Make sure there is a dot at Dot_Index. This may not be the case
+         --  if the source file name has no extension.
+
+         Name_Buffer (Dot_Index) := '.';
+
          --  Remove extension preparing to replace it
 
          declare