[Bug rtl-optimization/65235] [4.8/4.9/5 Regression] Simplifying vec_select of vec_concat miscompiles when first element of vec_concat is const_int

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65235

--- Comment #5 from ktkachov at gcc dot gnu.org ---
Created attachment 34891
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34891&action=edit
Self-contained testcase

Here's a testcase with the relevant parts of arm_neon.h extracted.

This aborts for me on aarch64-none-linux-gnu and aarch64-none-elf