[llvm] [MIR] Support save/restore points with independent sets of registers (PR #119358)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-nvptx64-nvidia-ubuntu` running on `as-builder-7` while building `llvm` at step 6 "test-build-unified-tree-check-llvm".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/160/builds/25383

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-llvm) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/MIR/X86/frame-info-save-restore-points-with-regs-parse.mir' FAILED ********************
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 1
/home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/build/bin/llc -run-pass none -o - /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/llvm-project/llvm/test/CodeGen/MIR/X86/frame-info-save-restore-points-with-regs-parse.mir | /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/build/bin/FileCheck /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/llvm-project/llvm/test/CodeGen/MIR/X86/frame-info-save-restore-points-with-regs-parse.mir
# executed command: /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/build/bin/llc -run-pass none -o - /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/llvm-project/llvm/test/CodeGen/MIR/X86/frame-info-save-restore-points-with-regs-parse.mir
# .---command stderr------------
# | error: YAML:114:3: unknown key 'amxProgModel'
# |   amxProgModel:    None
# |   ^~~~~~~~~~~~
# | 
# `-----------------------------
# error: command failed with exit status: 1
# executed command: /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/build/bin/FileCheck /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/llvm-project/llvm/test/CodeGen/MIR/X86/frame-info-save-restore-points-with-regs-parse.mir
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/build/bin/FileCheck /home/buildbot/worker/as-builder-7/llvm-nvptx64-nvidia-ubuntu/llvm-project/llvm/test/CodeGen/MIR/X86/frame-info-save-restore-points-with-regs-parse.mir
# `-----------------------------
# error: command failed with exit status: 2

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/119358