Simplify Win LLVM path under src/third_party (#1366)

As a preparation to support Windows ARM64 build hosts (#1296), with this
commit Windows LLVM archives are extracted as

  third_party/llvm/bin/...
  third_party/llvm/lib/...
  third_party/llvm/include/...

rather than

  third_party/llvm/clang+llvm-20.1.1-x86_64-pc-windows-msvc/bin/...
  third_party/llvm/clang+llvm-20.1.1-x86_64-pc-windows-msvc/lib/...
  third_party/llvm/clang+llvm-20.1.1-x86_64-pc-windows-msvc/include/...

This simplification will allow src/bazel/bazel_wrapper/bazel.bat to use
the same BAZEL_LLVM environment variable even after we start using a
different LLVM archive only on Windows ARM64 hosts.

This is just a code refactoring and should not change any behavior in
the final artifacts.

PiperOrigin-RevId: 816143880

Author: yukawa

src/bazel/bazel_wrapper/bazel.bat

@@ -4,8 +4,8 @@ set TMP_MOZC_BAZEL_WRAPPER_DIR=%~dp0
 set TMP_MOZC_SRC_DIR=%TMP_MOZC_BAZEL_WRAPPER_DIR:~0,-21%
 
 rem set BAZEL_LLVM only if clang-cl exists under third_party/llvm.
-set TMP_MOZC_LLVM_DIR=%TMP_MOZC_SRC_DIR%\third_party\llvm\clang+llvm-20.1.1-x86_64-pc-windows-msvc
-if exist %TMP_MOZC_LLVM_DIR% set BAZEL_LLVM=%TMP_MOZC_LLVM_DIR%
+set TMP_MOZC_LLVM_DIR=%TMP_MOZC_SRC_DIR%\third_party\llvm
+if exist %TMP_MOZC_LLVM_DIR%\bin\clang-cl.exe set BAZEL_LLVM=%TMP_MOZC_LLVM_DIR%
 set TMP_MOZC_LLVM_DIR=
 
 rem set BAZEL_SH only if MSYS2 exists under third_party/msys64/bin/bash.exe.

src/build_tools/update_deps.py

@@ -294,11 +294,12 @@ def __call__(
       skipping = False
     elif len(paths) >= 2 and paths[1] in ['include', 'lib']:
       skipping = False
+    new_path = '/'.join(paths[1:])
     if skipping:
-      self.printer.print_line('skipping   ' + member.name)
+      self.printer.print_line('skipping   ' + new_path)
       return None
-    self.printer.print_line('extracting ' + member.name)
-    return member
+    self.printer.print_line('extracting ' + new_path)
+    return member.replace(name=new_path, deep=False)
 
 
 def extract_llvm(dryrun: bool = False) -> None: