[clang] [CIR] Upstream vec shuffle builtins in CIR codegen (PR #169178)

[Andy Kaylor via cfe-commits]

https://github.com/andykaylor commented:

This looks great except for a small issue with the tests. Unfortunately, I have just rearranged the test directory, so you'll need to rebase this. Hopefully, git will be able to figure out what happened and automatically move your changes to the existing files during the rebase. You'll need to manually move the new tests you're introducing.

https://github.com/llvm/llvm-project/pull/169178