[llvm] [X86] Sync scalar hadd/hsub tests between the middle-end and backend (PR #207163)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clangd-ubuntu-tsan` running on `clangd-ubuntu-clang` while building `llvm` at step 6 "test-build-clangd-clangd-index-server-clangd-in...".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/134/builds/43063

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

```
Step 6 (test-build-clangd-clangd-index-server-clangd-in...) failure: test (failure)
******************** TEST 'Clangd :: crash-preamble.test' FAILED ********************
Exit Code: 66

Command Output (stdout):
--
# RUN: at line 1
not --crash clangd -lit-test < /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/clang-tools-extra/clangd/test/crash-preamble.test 2> /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/tools/clang/tools/extra/clangd/test/Output/crash-preamble.test.tmp.err
# executed command: not --crash clangd -lit-test
# .---command stdout------------
# | Content-Length: 3446
# | 
# | {
# |   "id": 0,
# |   "jsonrpc": "2.0",
# |   "result": {
# |     "capabilities": {
# |       "astProvider": true,
# |       "callHierarchyProvider": true,
# |       "clangdInlayHintsProvider": true,
# |       "codeActionProvider": true,
# |       "compilationDatabase": {
# |         "automaticReload": true
# |       },
# |       "completionProvider": {
# |         "resolveProvider": false,
# |         "triggerCharacters": [
# |           ".",
# |           "<",
# |           ">",
# |           ":",
# |           "\"",
# |           "/",
# |           "*"
# |         ]
# |       },
# |       "declarationProvider": true,
# |       "definitionProvider": true,
# |       "documentFormattingProvider": true,
# |       "documentHighlightProvider": true,
# |       "documentLinkProvider": {
# |         "resolveProvider": false
# |       },
# |       "documentOnTypeFormattingProvider": {
# |         "firstTriggerCharacter": "\n",
# |         "moreTriggerCharacter": []
# |       },
# |       "documentRangeFormattingProvider": {
# |         "rangesSupport": true
# |       },
# |       "documentSymbolProvider": true,
...

```

</details>

https://github.com/llvm/llvm-project/pull/207163