[llvm] [AArch64] Disable by default MachineSink sink-and-fold (PR #70101)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

> @bgra8 any reduced test case?
> 
> We've bisected a size regression to this commit.

Ah I see the discussion on https://github.com/llvm/llvm-project/pull/67432

https://github.com/llvm/llvm-project/pull/70101