[llvm] [NFC][ARM][MC] Rearrange decoder functions 2/N (PR #155464)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `cross-project-tests-sie-ubuntu` running on `doug-worker-1a` while building `llvm` at step 6 "test-build-unified-tree-check-cross-project".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/181/builds/26998

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

```
Step 6 (test-build-unified-tree-check-cross-project) failure: test (failure)
******************** TEST 'cross-project-tests :: debuginfo-tests/dexter-tests/vla.c' FAILED ********************
Exit Code: 2

Command Output (stdout):
--
vla.c: nan/nan (nan) [Command '['/usr/bin/python3.8', '/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/cross-project-tests/debuginfo-tests/dexter/dex/../dexter.py', 'run-debugger-internal-', '/tmp/lit-tmp-fe4ufox4/dexter/tmp6_srdton/tmpwt0zldhp', '--working-directory=/tmp/lit-tmp-fe4ufox4/dexter/tmp6_srdton', '--unittest=off', '--indent-timer-level=3']' returned non-zero exit status 1.]


--
Command Output (stderr):
--
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/clang -std=gnu11 -O0 -glldb /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/cross-project-tests/debuginfo-tests/dexter-tests/vla.c -o /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/projects/cross-project-tests/debuginfo-tests/dexter-tests/Output/vla.c.tmp # RUN: at line 5
+ /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/clang -std=gnu11 -O0 -glldb /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/cross-project-tests/debuginfo-tests/dexter-tests/vla.c -o /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/projects/cross-project-tests/debuginfo-tests/dexter-tests/Output/vla.c.tmp
"/usr/bin/python3.8" "/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/cross-project-tests/debuginfo-tests/dexter/dexter.py" test --fail-lt 1.0 -w --binary /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/projects/cross-project-tests/debuginfo-tests/dexter-tests/Output/vla.c.tmp --lldb-executable "/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/lldb-dap" --debugger lldb-dap -- /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/cross-project-tests/debuginfo-tests/dexter-tests/vla.c # RUN: at line 6
+ /usr/bin/python3.8 /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/cross-project-tests/debuginfo-tests/dexter/dexter.py test --fail-lt 1.0 -w --binary /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/projects/cross-project-tests/debuginfo-tests/dexter-tests/Output/vla.c.tmp --lldb-executable /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/lldb-dap --debugger lldb-dap -- /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/cross-project-tests/debuginfo-tests/dexter-tests/vla.c


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


```

</details>

https://github.com/llvm/llvm-project/pull/155464