[clang] [Clang] Fix integer promotion of bit-fields in statement expressions (PR #225597)

[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/66154

<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/stmtexprs.c' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# 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/include -nostdsysteminc /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c -verify -pedantic -fsyntax-only -Wno-gnu-statement-expression
# executed command: /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/include -nostdsysteminc /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c -verify -pedantic -fsyntax-only -Wno-gnu-statement-expression
# .---command stderr------------
# | error: 'expected-warning' diagnostics seen but not expected: 
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 16: '_Static_assert' is a C11 extension
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 16: '_Generic' is a C11 extension
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 18: '_Static_assert' is a C11 extension
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 18: '_Generic' is a C11 extension
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 20: '_Static_assert' is a C11 extension
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 20: '_Generic' is a C11 extension
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 22: '_Static_assert' is a C11 extension
# |   File /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/Sema/stmtexprs.c Line 22: '_Generic' is a C11 extension
# | 8 errors generated.
# `-----------------------------
# error: command failed with exit status: 1

--

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


```

</details>

https://github.com/llvm/llvm-project/pull/225597