[Ada] Syntax error in Ada 2022 array aggregate causes bug box

[Marc Poulhiès via Gcc-patches]

Check for the case where a user writes "in" instead of "of" in an
aggregate like "[for E in Some_Array when Some_Filter (E) => E]".

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

gcc/ada/

        * sem_aggr.adb
        (Resolve_Array_Aggregate): Generate an appropriate error message
        in the case where an error in the source code leads to an
        N_Iterated_Element_Association node in a bad context.
diff --git a/gcc/ada/sem_aggr.adb b/gcc/ada/sem_aggr.adb
--- a/gcc/ada/sem_aggr.adb
+++ b/gcc/ada/sem_aggr.adb
@@ -1987,6 +1987,11 @@ package body Sem_Aggr is
          while Present (Assoc) loop
             if Nkind (Assoc) = N_Iterated_Component_Association then
                Resolve_Iterated_Component_Association (Assoc, Index_Typ);
+
+            elsif Nkind (Assoc) /= N_Component_Association then
+               Error_Msg_N
+                 ("invalid component association for aggregate", Assoc);
+               return Failure;
             end if;
 
             Choice := First (Choice_List (Assoc));