[llvm] [AArch64] Reassociate adds/subs of extends for [SU](ADD|SUB)L. (PR #222561)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-aarch64-darwin` running on `doug-worker-5` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/49759

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: Object/AArch64/chained-fixups-header.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml    | sed 's/__LINKEDIT:      00000000/__LINKEDIT:      AB000000/'    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/not /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/llvm-objdump --macho --dyld-info - 2>&1    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/chained-fixups-header.test --check-prefix=HEADER1
# executed command: cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml
# note: command had no output on stdout or stderr
# executed command: sed 's/__LINKEDIT:      00000000/__LINKEDIT:      AB000000/'
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/not /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/llvm-objdump --macho --dyld-info -
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/chained-fixups-header.test --check-prefix=HEADER1
# note: command had no output on stdout or stderr
# RUN: at line 8
cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml    | sed 's/1000000010000000/1000000AB0000000/'    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/not /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/llvm-objdump --macho --dyld-info - 2>&1    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/chained-fixups-header.test --check-prefix=HEADER2
# executed command: cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml
# note: command had no output on stdout or stderr
# executed command: sed s/1000000010000000/1000000AB0000000/
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/not /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/llvm-objdump --macho --dyld-info -
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/chained-fixups-header.test --check-prefix=HEADER2
# note: command had no output on stdout or stderr
# RUN: at line 14
cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml    | sed 's/20000000/01000000/'    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/not /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/llvm-objdump --macho --dyld-info - 2>&1    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/chained-fixups-header.test --check-prefix=HEADER3
# executed command: cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml
# note: command had no output on stdout or stderr
# executed command: sed s/20000000/01000000/
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/not /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/llvm-objdump --macho --dyld-info -
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/chained-fixups-header.test --check-prefix=HEADER3
# note: command had no output on stdout or stderr
# RUN: at line 20
cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml    | sed 's/20000000/FF000000/'    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/not /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/llvm-objdump --macho --dyld-info - 2>&1    | /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/chained-fixups-header.test --check-prefix=HEADER4
# executed command: cat /Users/buildbot/buildbot-root2/aarch64-darwin/llvm-project/llvm/test/Object/AArch64/../Inputs/MachO/chained-fixups.yaml
# note: command had no output on stdout or stderr
# executed command: sed s/20000000/FF000000/
# note: command had no output on stdout or stderr
# executed command: /Volumes/ExternalSSD/buildbot-root/aarch64-darwin/build/bin/yaml2obj
# .---command stderr------------
# | YAML:140:5: error: missing required key 'cmdsize'
...

```

</details>

https://github.com/llvm/llvm-project/pull/222561