[Ada] Fix error with pragma Linker_Section

[Eric Botcazou]

The compiler may refuse to apply pragma Linker_Section with the same section 
name to two different variables, if one is considered constant by the compiler 
but not declared as such.  Fixed thusly.

Tested on x86_64-suse-linux, applied on the mainline.


2014-01-25  Tristan Gingold  <ging...@adacore.com>

        * gcc-interface/decl.c (gnat_to_gnu_entity): Always build a variable
        for E_Variable with a pragma Linker_Section.


-- 
Eric Botcazou
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c	(revision 207071)
+++ gcc-interface/decl.c	(working copy)
@@ -575,9 +575,13 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
       /* Simple variables, loop variables, Out parameters and exceptions.  */
     object:
       {
+	/* Always create a variable for volatile objects and variables seen
+	   constant but with a Linker_Section pragma.  */
 	bool const_flag
 	  = ((kind == E_Constant || kind == E_Variable)
 	     && Is_True_Constant (gnat_entity)
+	     && !(kind == E_Variable
+		  && Present (Linker_Section_Pragma (gnat_entity)))
 	     && !Treat_As_Volatile (gnat_entity)
 	     && (((Nkind (Declaration_Node (gnat_entity))
 		   == N_Object_Declaration)