[clang] [AArch64] Add missing Neon Types (PR #126945)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

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

Full details are available at: https://lab.llvm.org/buildbot/#/builders/3/builds/16870

<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 'Clang :: CodeGen/AArch64/mixed-neon-types.c' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
/buildbot/worker/arc-folder/build/bin/clang -cc1 -internal-isystem /buildbot/worker/arc-folder/build/lib/clang/21/include -nostdsysteminc  -triple aarch64-linux-gnu -target-feature +neon -x c /buildbot/worker/arc-folder/llvm-project/clang/test/CodeGen/AArch64/mixed-neon-types.c -emit-llvm -o - | /buildbot/worker/arc-folder/build/bin/FileCheck /buildbot/worker/arc-folder/llvm-project/clang/test/CodeGen/AArch64/mixed-neon-types.c --check-prefix=CHECK-C # RUN: at line 2
+ /buildbot/worker/arc-folder/build/bin/clang -cc1 -internal-isystem /buildbot/worker/arc-folder/build/lib/clang/21/include -nostdsysteminc -triple aarch64-linux-gnu -target-feature +neon -x c /buildbot/worker/arc-folder/llvm-project/clang/test/CodeGen/AArch64/mixed-neon-types.c -emit-llvm -o -
+ /buildbot/worker/arc-folder/build/bin/FileCheck /buildbot/worker/arc-folder/llvm-project/clang/test/CodeGen/AArch64/mixed-neon-types.c --check-prefix=CHECK-C
/buildbot/worker/arc-folder/llvm-project/clang/test/CodeGen/AArch64/mixed-neon-types.c:27:10: fatal error: 'arm_neon.h' file not found
   27 | #include <arm_neon.h>
      |          ^~~~~~~~~~~~
1 error generated.
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /buildbot/worker/arc-folder/build/bin/FileCheck /buildbot/worker/arc-folder/llvm-project/clang/test/CodeGen/AArch64/mixed-neon-types.c --check-prefix=CHECK-C

--

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


```

</details>

https://github.com/llvm/llvm-project/pull/126945