[gcc r11-8271] Add stopgap fix for PR ada/99360

[gcc r11-8271] Add stopgap fix for PR ada/99360

[Eric Botcazou]

https://gcc.gnu.org/g:53e85b38aaa10f5f8fe35eeea454a92c293cbc67

commit r11-8271-g53e85b38aaa10f5f8fe35eeea454a92c293cbc67
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Wed Apr 21 11:18:21 2021 +0200

    Add stopgap fix for PR ada/99360
    
    gcc/ada/
            PR ada/99360
            * exp_ch6.adb (Might_Have_Tasks): Return False when the type is the
            class-wide type of a predefined iterator type.

Diff:
---
 gcc/ada/exp_ch6.adb | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/exp_ch6.adb b/gcc/ada/exp_ch6.adb
index 2cd40e42f47..c1dc371786d 100644
--- a/gcc/ada/exp_ch6.adb
+++ b/gcc/ada/exp_ch6.adb
@@ -9616,7 +9616,15 @@ package body Exp_Ch6 is
         and then not No_Run_Time_Mode
         and then (Has_Task (Typ)
                     or else (Is_Class_Wide_Type (Typ)
-                               and then Is_Limited_Record (Typ)));
+                               and then Is_Limited_Record (Typ)))
+
+        --  Predefined iterator types do not contain tasks, even when
+        --  class-wide.
+
+        and then not (In_Predefined_Unit (Typ)
+                        and then Chars (Typ) in
+                          Name_Find ("Tforward_iteratorC") |
+                          Name_Find ("Treversible_iteratorC"));
    end Might_Have_Tasks;
 
    ----------------------------