[clang] [Clang][AArch64] Remove unwarranted 'cannot be used in non-streaming mode' diagnostic. (PR #150592)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-sie-ubuntu-fast` running on `sie-linux-worker` while building `clang` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/144/builds/31604

<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 :: Sema/aarch64-sme-attrs-without-sve.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/clang -cc1 -internal-isystem /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/lib/clang/22/include -nostdsysteminc -triple aarch64-none-linux-gnu -target-feature +sme -fsyntax-only -verify /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp # RUN: at line 1
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/clang -cc1 -internal-isystem /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/lib/clang/22/include -nostdsysteminc -triple aarch64-none-linux-gnu -target-feature +sme -fsyntax-only -verify /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp
error: 'expected-error' diagnostics expected but not seen: 
  File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp Line 10: SVE vector type 'svint32_t' (aka '__SVInt32_t') cannot be used in a non-streaming function
  File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp Line 10: SVE vector type 'svint32_t' (aka '__SVInt32_t') cannot be used in a non-streaming function
  File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp Line 25: SVE vector type 'svint32_t' (aka '__SVInt32_t') cannot be used in a non-streaming function
  File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp Line 43: SVE vector type 'svint32_t' (aka '__SVInt32_t') cannot be used in a non-streaming function
  File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp Line 52: SVE vector type 'svint32_t' (aka '__SVInt32_t') cannot be used in a non-streaming function
error: 'expected-error' diagnostics seen but not expected: 
  File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/aarch64-sme-attrs-without-sve.cpp Line 3: 'arm_sme.h' file not found
6 errors generated.

--

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


```

</details>

https://github.com/llvm/llvm-project/pull/150592