[llvm] [AArch64] New pass for code layout optimizations. (PR #184434)

[Eli Friedman via llvm-commits]

https://github.com/efriedma-quic commented:

What is the ultimate goal here?

At first glance, this looks like it detects the instruction pair, and... sets the function alignment.  Which doesn't actually ensure anything about the pair itself; it just reduces noise from changes to other functions.

https://github.com/llvm/llvm-project/pull/184434