[Bug middle-end/70434] [5/6 Regression] adding an extraneous cast to vector type results in inferior code

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70434

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think the point of the bug is that we generate different code - expecting
"efficient" code from variable indexing is not really expected.

So not sure how a testcase would best look like.