[clang] Switch builtin strings to use string tables (PR #118734)

[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/9169

<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 :: AST/builtins-arm-strex-rettype.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 thumbv7m-apple-darwin-eabi -ast-dump Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\AST\builtins-arm-strex-rettype.c | z:\b\llvm-clang-x86_64-sie-win\build\bin\filecheck.exe Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\AST\builtins-arm-strex-rettype.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 thumbv7m-apple-darwin-eabi -ast-dump 'Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\AST\builtins-arm-strex-rettype.c'
# .---command stderr------------
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\clang\test\AST\builtins-arm-strex-rettype.c:7:12: error: use of unknown builtin '__builtin_arm_strex' [-Wimplicit-function-declaration]
# |     7 |   } while (__builtin_arm_strex(a, b));
# |       |            ^
# | 1 error generated.
# `-----------------------------
# 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\AST\builtins-arm-strex-rettype.c'

--

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


```

</details>

https://github.com/llvm/llvm-project/pull/118734