[llvm] Initialize PreferredAlign in Function (PR #192156)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

Do you have a test case that exposes this with msan/asan? I'm surprised we haven't seen this with any of our internal sanitizer enabled testing.

https://github.com/llvm/llvm-project/pull/192156