[Ada] Inlining nonstatic calls to static expression functions

[Pierre-Marie de Rodat]

Static expression functions were already effectively inlined in the
case of calls to them with static arguments, but calls with nonstatic
arguments were not generally being inlined, but now they are, as a result
of setting the Has_Pragma_Inline and Is_Inlined flags on such functions.
It appears that it isn't strictly necessary to set the latter flag,
but it still seems reasonable to set it and may be needed in general.

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

gcc/ada/

        * sem_ch6.adb (Analyze_Expression_Function): Mark static
        expression functions as inlined.
diff --git a/gcc/ada/sem_ch6.adb b/gcc/ada/sem_ch6.adb
--- a/gcc/ada/sem_ch6.adb
+++ b/gcc/ada/sem_ch6.adb
@@ -609,6 +609,12 @@ package body Sem_Ch6 is
                   Set_Expression
                     (Original_Node (Subprogram_Spec (Def_Id)),
                      New_Copy_Tree (Expr));
+
+                  --  Mark static expression functions as inlined, to ensure
+                  --  that even calls with nonstatic actuals will be inlined.
+
+                  Set_Has_Pragma_Inline (Def_Id);
+                  Set_Is_Inlined (Def_Id);
                end if;
             end if;
          end;