[lldb] [llvm] Add AArch64 support to the premerge tests (PR #155274)

[Tom Stellard via llvm-commits]

tstellar wrote:

This is ready for review.  I set the continue-on-error property for the aarch64 tests for now to allow for a stabilization period that doesn't impact users.

https://github.com/llvm/llvm-project/pull/155274