[gcc r16-2339] ada: Back out change to Tbuild.Unchecked_Convert_To

[Marc Poulhies via Gcc-cvs]

https://gcc.gnu.org/g:8c828583366c8b3877cc4488749b72e954b5df64

commit r16-2339-g8c828583366c8b3877cc4488749b72e954b5df64
Author: Bob Duff <d...@adacore.com>
Date:   Fri Jun 27 12:00:54 2025 -0400

    ada: Back out change to Tbuild.Unchecked_Convert_To
    
    ...because it breaks one test that uses --RTS=light.
    "Is_Composite_Type" is needed; "not Is_Scalar_Type"
    was wrong.
    
    gcc/ada/ChangeLog:
    
            * tbuild.adb (Unchecked_Convert_To): Back out
            change.

Diff:
---
 gcc/ada/tbuild.adb | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/gcc/ada/tbuild.adb b/gcc/ada/tbuild.adb
index b89c40851bc1..52fdbfc2163f 100644
--- a/gcc/ada/tbuild.adb
+++ b/gcc/ada/tbuild.adb
@@ -926,11 +926,11 @@ package body Tbuild is
       --  conversion of an unchecked conversion. Extra unchecked conversions
       --  make the .dg output less readable. We can't do this in cases
       --  involving bitfields, because the sizes might not match. The
-      --  "not Is_Scalar_Type" checks avoid such cases.
+      --  Is_Composite_Type checks avoid such cases.
 
       elsif Nkind (Expr) = N_Unchecked_Type_Conversion
-        and then not Is_Scalar_Type (Etype (Expr))
-        and then not Is_Scalar_Type (Typ)
+        and then Is_Composite_Type (Etype (Expr))
+        and then Is_Composite_Type (Typ)
       then
          Set_Subtype_Mark (Expr, New_Occurrence_Of (Typ, Loc));
          Result := Relocate_Node (Expr);