[Bug target/100941] wrong code with __builtin_shufflevector() with -mavx512f

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100941

--- Comment #2 from Zdenek Sojka <zsojka at seznam dot cz> ---
(In reply to Hongtao.liu from comment #1)
> The issue seems to be related to generic part, not target specific
> 
> 006t.gimple
> 
> U foo (V v, W w)
> {
>   U D.2852;
> 
>   _1 = {v, { 0, 0, 0, 0 }};
>   _2 = BIT_INSERT_EXPR <_1, { 0, 0, 0, 0 }, 0>; <--- why bit position is 0
> but not 256?
>   D.2852 = BIT_FIELD_REF <_2, 64, 0>;
>   return D.2852;
> }

Thank you for having a look.
I will re-check with the PR100887 fix applied.