[clang] [Win/X86] Make _m_prefetch[w] builtins to avoid winnt.h conflicts (PR #115099)

[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 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/56/builds/17817

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build-unified-tree) failure: build (failure)
...
0.325 [5621/91/429] Building arm_sme_streaming_attrs.inc...
0.325 [5621/90/430] Building arm_sme_builtins_za_state.inc...
0.325 [5621/89/431] Building arm_cde_builtins.inc...
0.325 [5621/88/432] Building arm_cde_builtin_cg.inc...
0.325 [5621/87/433] Building arm_cde_builtin_aliases.inc...
0.325 [5621/86/434] Building riscv_sifive_vector_builtins.inc...
0.325 [5621/85/435] Building riscv_sifive_vector_builtin_cg.inc...
0.325 [5621/84/436] Building riscv_sifive_vector_builtin_sema.inc...
0.326 [5621/83/437] Building arm_sve_streaming_attrs.inc...
0.326 [5621/82/438] Building BuiltinsX86.inc...
FAILED: tools/clang/include/clang/Basic/BuiltinsX86.inc /b/1/clang-x86_64-debian-fast/llvm.obj/tools/clang/include/clang/Basic/BuiltinsX86.inc 
cd /b/1/clang-x86_64-debian-fast/llvm.obj && /b/1/clang-x86_64-debian-fast/llvm.obj/bin/clang-tblgen -gen-clang-builtins -I /b/1/clang-x86_64-debian-fast/llvm.src/clang/include/clang/Basic -I/b/1/clang-x86_64-debian-fast/llvm.src/clang/include -I/b/1/clang-x86_64-debian-fast/llvm.obj/tools/clang/include -I/b/1/clang-x86_64-debian-fast/llvm.obj/include -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include /b/1/clang-x86_64-debian-fast/llvm.src/clang/include/clang/Basic/BuiltinsX86.td --write-if-changed -o tools/clang/include/clang/Basic/BuiltinsX86.inc -d tools/clang/include/clang/Basic/BuiltinsX86.inc.d
/b/1/clang-x86_64-debian-fast/llvm.src/clang/include/clang/Basic/BuiltinsX86.td:147:7: error: Unexpected header name
  def _m_prefetch : X86LibBuiltin<"void(void *)">;
      ^
0.326 [5621/81/439] Building arm_sme_builtin_cg.inc...
0.326 [5621/80/440] Building arm_cde_builtin_sema.inc...
0.326 [5621/79/441] Building Nodes.inc...
0.326 [5621/78/442] Building NodeClasses.inc...
0.326 [5621/77/443] Building arm_fp16.h...
0.326 [5621/76/444] Building Checkers.inc...
0.326 [5621/75/445] Building arm_sme_sema_rangechecks.inc...
0.327 [5621/74/446] Building arm_bf16.h...
0.329 [5621/73/447] Building arm_cde.h...
0.331 [5621/72/448] Building arm_neon.inc...
0.332 [5621/71/449] Building AttrParserStringSwitches.inc...
0.332 [5621/70/450] Building arm_mve_builtins.inc...
0.334 [5621/69/451] Building AttrSubMatchRulesParserStringSwitches.inc...
0.335 [5621/68/452] Building arm_vector_types.h...
0.335 [5621/67/453] Building AttrTemplateInstantiate.inc...
0.336 [5621/66/454] Building AttrSpellingListIndex.inc...
0.336 [5621/65/455] Building AttrPCHRead.inc...
0.337 [5621/64/456] Building AttrPCHWrite.inc...
0.337 [5621/63/457] Building arm_sme.h...
0.337 [5621/62/458] Building AttrParsedAttrKinds.inc...
0.347 [5621/61/459] Building DiagnosticFrontendEnums.inc...
0.347 [5621/60/460] Building DiagnosticDriverEnums.inc...
0.350 [5621/59/461] Building DiagnosticCommonEnums.inc...
0.351 [5621/58/462] Building DiagnosticRefactoringEnums.inc...
0.351 [5621/57/463] Building DiagnosticASTEnums.inc...
0.353 [5621/56/464] Building DiagnosticCommentEnums.inc...
0.355 [5621/55/465] Building DiagnosticIndexName.inc...
0.356 [5621/54/466] Building DiagnosticCommentKinds.inc...
0.356 [5621/53/467] Building DiagnosticSerializationEnums.inc...
0.356 [5621/52/468] Building DiagnosticAnalysisEnums.inc...
0.358 [5621/51/469] Building DiagnosticAnalysisKinds.inc...
0.358 [5621/50/470] Building DiagnosticLexKinds.inc...
0.358 [5621/49/471] Building DiagnosticParseEnums.inc...
0.358 [5621/48/472] Building DiagnosticCrossTUKinds.inc...

```

</details>

https://github.com/llvm/llvm-project/pull/115099