[clang] [CLANG][AArch64] Add the modal 8 bit floating-point scalar type (PR #97277)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-sie-win` running on `sie-win-worker` while building `clang` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/46/builds/6850

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

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: CodeGen/aarch64-debug-types.c' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
z:\b\llvm-clang-x86_64-sie-win\build\bin\clang.exe -cc1 -internal-isystem Z:\b\llvm-clang-x86_64-sie-win\build\lib\clang\20\include -nostdsysteminc -triple aarch64-none-linux-gnu -target-feature +neon  -target-feature +fp8   -emit-llvm -o - Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c -debug-info-kind=limited 2>&1 | z:\b\llvm-clang-x86_64-sie-win\build\bin\filecheck.exe Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c
# executed command: 'z:\b\llvm-clang-x86_64-sie-win\build\bin\clang.exe' -cc1 -internal-isystem 'Z:\b\llvm-clang-x86_64-sie-win\build\lib\clang\20\include' -nostdsysteminc -triple aarch64-none-linux-gnu -target-feature +neon -target-feature +fp8 -emit-llvm -o - 'Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c' -debug-info-kind=limited
# note: command had no output on stdout or stderr
# error: command failed with exit status: 1
# executed command: 'z:\b\llvm-clang-x86_64-sie-win\build\bin\filecheck.exe' 'Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c'
# .---command stderr------------
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c:6:16: error: CHECK-DAG: expected string not found in input
# |  // CHECK-DAG: !DIDerivedType(tag: DW_TAG_typedef, name: "__MFloat8_t", {{.*}}, baseType: ![[ELTTYU8:[0-9]+]]
# |                ^
# | <stdin>:1:1: note: scanning from here
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c:3:9: fatal error: 'arm_neon.h' file not found
# | ^
# | 
# | Input file: <stdin>
# | Check file: Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |        1: Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\CodeGen\aarch64-debug-types.c:3:9: fatal error: 'arm_neon.h' file not found 
# | dag:6     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
# |        2:  3 | #include<arm_neon.h> 
# | dag:6     ~~~~~~~~~~~~~~~~~~~~~~~~~~
# |        3:  | ^~~~~~~~~~~~ 
# | dag:6     ~~~~~~~~~~~~~~~~
# |        4: 1 error generated. 
# | dag:6     ~~~~~~~~~~~~~~~~~~~
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

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


```

</details>

https://github.com/llvm/llvm-project/pull/97277