ada: Get rid of Kill_Range_Checks flag on entities

This flag is set in a single context, namely semantic analysis of record
type definitions, to avoid generating spurious range checks from it, and
a large testing campaign showed that, in practice, it makes a difference
in a single case, namely an access-to-constrained-array component with a
default expression, for example:

  type Acc_String is access all String (1 .. 100);

  type Rec (D : Positive) is record
    A : Acc_String := new String (1 .. D);
  end record;

Now there is another mechanism implemented in Process_Range_Expr_In_Decl to
avoid generating spurious range checks, which does not work in this specific
case but can be made to work with a small tweak to Denotes_Discriminant.

gcc/ada/ChangeLog:

	* checks.adb (Range_Checks_Suppressed): Remove test on the
	Kill_Range_Checks flag.
	* einfo.ads (Kill_Range_Checks): Delete.
	* gen_il-fields.ads (Opt_Field_Enum): Remove Kill_Range_Checks.
	* gen_il-gen-gen_entities.adb (Entity_Kind): Likewise.
	* sem_ch3.adb (Record_Type_Declaration): Do not set the
	Kill_Range_Checks flag.
	* sem_util.adb (Denotes_Discriminant): In a default expression,
	also return True for a discriminal.

1 files changed, 1 insertions, 16 deletions

diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
index 28fc25d..aa95069 100644
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -23079,22 +23079,7 @@ package body Sem_Ch3 is
          Set_Direct_Primitive_Operations (T, New_Elmt_List);
       end if;
 
-      --  We must suppress range checks when processing record components in
-      --  the presence of discriminants, since we don't want spurious checks to
-      --  be generated during their analysis, but Suppress_Range_Checks flags
-      --  must be reset the after processing the record definition.
-
-      --  Note: this is the only use of Kill_Range_Checks, and is a bit odd,
-      --  couldn't we just use the normal range check suppression method here.
-      --  That would seem cleaner ???
-
-      if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
-         Set_Kill_Range_Checks (T, True);
-         Record_Type_Definition (Def, Prev);
-         Set_Kill_Range_Checks (T, False);
-      else
-         Record_Type_Definition (Def, Prev);
-      end if;
+      Record_Type_Definition (Def, Prev);
 
       --  Exit from record scope