[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 `clangd-ubuntu-tsan` running on `clangd-ubuntu-clang` while building `clang` at step 5 "build-clangd-clangd-index-server-clangd-indexer".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/134/builds/12872

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

```
Step 5 (build-clangd-clangd-index-server-clangd-indexer) failure: build (failure)
...
17.720 [4292/18/437] Building StmtDataCollectors.inc...
17.720 [4291/18/438] Building BuiltinsSPIRV.inc...
17.721 [4290/18/439] Building AttrVisitor.inc...
17.728 [4289/18/440] Building BuiltinsRISCV.inc...
17.728 [4288/18/441] Building DiagnosticCrossTUEnums.inc...
17.729 [4287/18/442] Building BuiltinsX86_64.inc...
17.729 [4286/18/443] Building arm_fp16.inc...
17.737 [4285/18/444] Building DiagnosticDriverKinds.inc...
17.737 [4284/18/445] Building DiagnosticFrontendEnums.inc...
17.738 [4283/18/446] Building BuiltinsX86.inc...
FAILED: tools/clang/include/clang/Basic/BuiltinsX86.inc /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/tools/clang/include/clang/Basic/BuiltinsX86.inc 
cd /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build && /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/NATIVE/bin/clang-tblgen -gen-clang-builtins -I /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/clang/include/clang/Basic -I/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/clang/include -I/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/tools/clang/include -I/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/include -I/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/llvm/include /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/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
/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/clang/include/clang/Basic/BuiltinsX86.td:147:7: error: Unexpected header name
  def _m_prefetch : X86LibBuiltin<"void(void *)">;
      ^
17.742 [4283/17/447] Building arm_immcheck_types.inc...
17.753 [4283/16/448] Building arm_sme_streaming_attrs.inc...
17.755 [4283/15/449] Building arm_sme_builtins.inc...
17.756 [4283/14/450] Building arm_sme_sema_rangechecks.inc...
17.761 [4283/13/451] Building arm_neon.inc...
17.761 [4283/12/452] Building arm_mve_builtin_sema.inc...
17.762 [4283/11/453] Building arm_mve_builtins.inc...
17.764 [4283/10/454] Building arm_mve_builtin_aliases.inc...
17.766 [4283/9/455] Building arm_sve_typeflags.inc...
17.772 [4283/8/456] Building arm_sme_builtin_cg.inc...
17.781 [4283/7/457] Building arm_mve_builtin_cg.inc...
17.787 [4283/6/458] Building arm_sve_streaming_attrs.inc...
17.845 [4283/5/459] Building arm_sve_builtins.inc...
17.847 [4283/4/460] Building arm_sve_builtin_cg.inc...
17.849 [4283/3/461] Building arm_sve_sema_rangechecks.inc...
18.409 [4283/2/462] Linking CXX executable bin/llvm-tblgen
18.559 [4283/1/463] Building AArch64TargetParserDef.inc...
ninja: build stopped: subcommand failed.

```

</details>

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