[llvm] MC: Remove bundle alignment mode (PR #148781)

[Sharjeel Khan via llvm-commits]

Sharjeel-Khan wrote:

Hey @MaskRay, we need bundle support for [LFI](https://github.com/lfi-project), a sandboxing project going to be used in Google. Is it possible we can revert this PR? We currently use .bundle_align_mode, .bundle_lock, and .bundle_unlock. Without them, It will make the project harder on x86-64.

https://github.com/llvm/llvm-project/pull/148781