[clang-tools-extra] [clang-tidy] Fix assert in performance-unnecessary-copy-init. (PR #96506)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-arm64-windows-msvc` running on `linaro-armv8-windows-msvc-04` while building `clang-tools-extra` at step 4 "build stage 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/161/builds/174

Here is the relevant piece of the build log for the reference:
```
Step 4 (build stage 1) failure: 'ninja' (failure)
...
[6095/7474] Linking CXX static library lib\clangTidyMain.lib
[6096/7474] Linking CXX executable bin\clang-include-cleaner.exe
[6097/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ClangdServer.cpp.obj
[6098/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FileDistance.cpp.obj
[6099/7474] Linking CXX executable bin\clang-tidy.exe
[6100/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FS.cpp.obj
[6101/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FuzzyMatch.cpp.obj
[6102/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/CodeComplete.cpp.obj
[6103/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/CompileCommands.cpp.obj
[6104/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.obj
FAILED: tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.obj 
ccache C:\PROGRA~1\LLVM\bin\clang-cl.exe  /nologo -TP -DGTEST_HAS_RTTI=0 -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_GLIBCXX_ASSERTIONS -D_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/stage1/tools/clang/tools/extra/clangd -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/llvm/clang-tools-extra/clangd -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/llvm/clang-tools-extra/clangd/../include-cleaner/include -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/stage1/tools/clang/tools/extra/clangd/../clang-tidy -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/llvm/clang/include -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/stage1/tools/clang/include -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/stage1/include -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/llvm/llvm/include -IC:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/llvm/clang-tools-extra/pseudo/lib/../include /DWIN32 /D_WINDOWS   /Zc:inline /Zc:__cplusplus /Oi /Brepro /bigobj /permissive- -Werror=unguarded-availability-new /W4  -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported /Gw /O2 /Ob2  -MD  /EHs-c- /GR- -UNDEBUG -std:c++17 /showIncludes /Fotools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.obj /Fdtools\clang\tools\extra\clangd\CMakeFiles\obj.clangDaemon.dir\ -c -- C:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/llvm/clang-tools-extra/clangd/Format.cpp
C:/Users/tcwg/llvm-worker/clang-arm64-windows-msvc/llvm/clang-tools-extra/clangd/Format.cpp(284,11): error: no member named 'KeepEmptyLinesAtTheStartOfBlocks' in 'clang::format::FormatStyle'
  284 |     Style.KeepEmptyLinesAtTheStartOfBlocks = true;
      |     ~~~~~ ^
1 error generated.
[6105/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FindSymbols.cpp.obj
[6106/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Diagnostics.cpp.obj
[6107/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ClangdLSPServer.cpp.obj
[6108/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/AST.cpp.obj
[6109/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/GlobalCompilationDatabase.cpp.obj
[6110/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Headers.cpp.obj
[6111/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/DumpAST.cpp.obj
[6112/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/HeaderSourceSwitch.cpp.obj
[6113/7474] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FindTarget.cpp.obj
ninja: build stopped: subcommand failed.

```

https://github.com/llvm/llvm-project/pull/96506