Backport [AArch64] Support for Ampere1 core

[ptomsich]

64816e6 [AArch64] Add native CPU detection for Ampere1
7e02bc5 [AArch64] Support for Ampere1 core

This adds support for the Ampere1 core to the 14.0.x series to support using the same Makefiles/scripts as with GCC (and the future LLVM 15).

Cherry-picked and tested w/o regressions against llvmorg-14.0.1

@kbeyls @davemgreen Ok to backport?

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

[kbeyls]

I see no issue with backporting these 2 patches, so it's OK from my perspective.

[ptomsich]

/cherry-pick 7e02bc5 64816e6

[llvmbot]

/branch llvmbot/llvm-project/issue55244

[llvmbot]

/pull-request llvmbot#190

[ptomsich]

Turns out that the MTE extension was turned on for Ampere1, which shouldn't have been.

So the following should additionally be included in the backport:
91b24b0 [AArch64] Ampere1 does not support MTE

[ptomsich]

/cherry-pick 91b24b0

[llvmbot]

Failed to cherry-pick: 91b24b0

https://github.com/llvm/llvm-project/actions/runs/2293275504

Please manually backport the fix and push it to your github fork. Once this is done, please add a comment like this:

/branch <user>/<repo>/<branch>