[llvm] 9936455 - Reapply D70800: Fix AArch64 AAPCS frame record chain

[Martin Storsjö via llvm-commits]

On Wed, 26 Aug 2020, Owen Anderson via llvm-commits wrote:

>
> Author: Owen Anderson
> Date: 2020-08-26T19:38:38Z
> New Revision: 9936455204fd6ab72715cc9d67385ddc93e072ed
>
> URL: https://github.com/llvm/llvm-project/commit/9936455204fd6ab72715cc9d67385ddc93e072ed
> DIFF: https://github.com/llvm/llvm-project/commit/9936455204fd6ab72715cc9d67385ddc93e072ed.diff
>
> LOG: Reapply D70800: Fix AArch64 AAPCS frame record chain

This commit caused failed assertions, so I went ahead and reverted it - 
see the revert commit message for a reduced reproduction case.

// Martin