[clang] [clang][x86] Add constexpr support for all remaining BMI1 intrinsics (PR #110581)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-x86_64-debian-fast` running on `gribozavr4` while building `clang` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/56/builds/8784

<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 :: Headers/x86-intrinsics-headers-clean.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 3: /b/1/clang-x86_64-debian-fast/llvm.obj/bin/clang -cc1 -internal-isystem /b/1/clang-x86_64-debian-fast/llvm.obj/lib/clang/20/include -nostdsysteminc -ffreestanding -triple i386-unknown-unknown     -Wextra -Werror -Wsystem-headers -Wsign-conversion -Wcast-qual -Wdocumentation -Wdocumentation-pedantic -Wdocumentation-unknown-command     -fsyntax-only -fretain-comments-from-system-headers -flax-vector-conversions=none -x c++ -verify /b/1/clang-x86_64-debian-fast/llvm.src/clang/test/Headers/x86-intrinsics-headers-clean.cpp
+ /b/1/clang-x86_64-debian-fast/llvm.obj/bin/clang -cc1 -internal-isystem /b/1/clang-x86_64-debian-fast/llvm.obj/lib/clang/20/include -nostdsysteminc -ffreestanding -triple i386-unknown-unknown -Wextra -Werror -Wsystem-headers -Wsign-conversion -Wcast-qual -Wdocumentation -Wdocumentation-pedantic -Wdocumentation-unknown-command -fsyntax-only -fretain-comments-from-system-headers -flax-vector-conversions=none -x c++ -verify /b/1/clang-x86_64-debian-fast/llvm.src/clang/test/Headers/x86-intrinsics-headers-clean.cpp
error: 'expected-error' diagnostics seen but not expected: 
  Line 195: duplicate 'constexpr' declaration specifier
1 error generated.

--

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


```

</details>

https://github.com/llvm/llvm-project/pull/110581