CodeQL seems to produce many warnings when compiling source that includes AVX-512 extensions

Hi there,

I'm filing this all as one bug in case they share a root cause, because it seems somewhat likely to me they all share the same root cause. Please let me know if that's not the case and I can parse these out into separate bug reports.

But: when compiling Chromium, we see a lot of warnings (on the order of ~190,000) related to the inclusion of the following Clang headers:

* avx512vlbf16intrin.h
* avx512vlfp16intrin.h
* avx512fintrin.h

Some sample warnings include:

```
Warning[extractor-c++]: In construct_text_message: "/b/s/w/ir/x/w/src/third_party/llvm-build/Release+Asserts/lib/clang/19/include/avx512vlbf16intrin.h", line 41: error: invalid type conversion
return (__m128bh)__builtin_ia32_cvtne2ps2bf16_128((__v4sf) __A,
^
```
and

```
Warning[extractor-c++]: In construct_text_message: "/b/s/w/ir/x/w/src/third_party/llvm-build/Release+Asserts/lib/clang/19/include/avx512vlbf16intrin.h", line 65: error: argument of type "__v8bf" is incompatible with parameter of type "__attribute((vector_size(32))) __bf16"
(__v8bf)_mm_cvtne2ps_pbh(__A, __B),
^
```

and

```
Warning[extractor-c++]: In construct_text_message: "/b/s/w/ir/x/w/src/third_party/llvm-build/Release+Asserts/lib/clang/19/include/avx512vlfp16intrin.h", line 967: error: invalid type conversion
return (__m128i)__builtin_ia32_vcvtph2udq128_mask(
^
```

and

```
Warning[extractor-c++]: In construct_text_message: "/b/s/w/ir/x/w/src/third_party/llvm-build/Release+Asserts/lib/clang/19/include/avx512fintrin.h", line 484: error: identifier "__builtin_nondeterministic_value" is undefined
__m256i __B = __builtin_nondeterministic_value(__B);
^
```

I'm wondering if this is already a known issue / something on the roadmap to support (perhaps SIMD-related code requires extra support)? If not, would it be helpful for me to provide a reproducer for one of these instances (as a representative sample), or do you think these in fact represent many different classes of issue and you'd like more of a breakdown than that?

Thanks very much!

Beginne damit, die Warnungen des CodeQL C++ extractors zu reproduzieren, während du Chromium mit den genannten Clang-Headern kompilierst: avx512vlbf16intrin.h, avx512vlfp16intrin.h und avx512fintrin.h. Vergleiche die Berichte zu ungültigen Konvertierungen, inkompatiblen Vektortypen und undefinierten Built-ins, um festzustellen, ob sie auf dasselbe extractor-Problem zurückgehen; abgeschlossen ist die Aufgabe, wenn die Ursache isoliert ist und die Warnungen behoben oder in umsetzbare Bugs aufgeteilt sind.

Vom Indexierungsmodell aus dem Issue-Text verfasst.