[clang] [clang-format] Add option to remove leading blank lines (PR #91221)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-armv7-2stage` running on `linaro-clang-armv7-2stage` while building `clang` at step 4 "build stage 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/79/builds/203

Here is the relevant piece of the build log for the reference:
```
Step 4 (build stage 1) failure: 'ninja' (failure)
...
[116/272] Building CXX object tools/clang/tools/extra/clang-include-fixer/plugin/CMakeFiles/obj.clangIncludeFixerPlugin.dir/IncludeFixerPlugin.cpp.o
[117/272] Linking CXX executable bin/pp-trace
[118/272] Linking CXX executable bin/clang-include-fixer
[119/272] Building CXX object tools/clang/tools/extra/include-cleaner/tool/CMakeFiles/clang-include-cleaner.dir/IncludeCleaner.cpp.o
[120/272] Linking CXX static library lib/libclangIncludeFixerPlugin.a
[121/272] Linking CXX executable bin/clang-check
[122/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/CollectMacros.cpp.o
[123/272] Building CXX object tools/clang/tools/extra/tool-template/CMakeFiles/tool-template.dir/ToolTemplate.cpp.o
[124/272] Building CXX object tools/clang/tools/extra/clang-move/CMakeFiles/obj.clangMove.dir/Move.cpp.o
[125/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.o
FAILED: tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.o 
/usr/local/bin/c++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/clang-armv7-2stage/stage1/tools/clang/tools/extra/clangd -I/home/tcwg-buildbot/worker/clang-armv7-2stage/llvm/clang-tools-extra/clangd -I/home/tcwg-buildbot/worker/clang-armv7-2stage/llvm/clang-tools-extra/clangd/../include-cleaner/include -I/home/tcwg-buildbot/worker/clang-armv7-2stage/stage1/tools/clang/tools/extra/clangd/../clang-tidy -I/home/tcwg-buildbot/worker/clang-armv7-2stage/llvm/clang/include -I/home/tcwg-buildbot/worker/clang-armv7-2stage/stage1/tools/clang/include -I/home/tcwg-buildbot/worker/clang-armv7-2stage/stage1/include -I/home/tcwg-buildbot/worker/clang-armv7-2stage/llvm/llvm/include -I/home/tcwg-buildbot/worker/clang-armv7-2stage/llvm/clang-tools-extra/pseudo/lib/../include -mcpu=cortex-a15 -marm -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.o -MF tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.o.d -o tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Format.cpp.o -c /home/tcwg-buildbot/worker/clang-armv7-2stage/llvm/clang-tools-extra/clangd/Format.cpp
../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.
[126/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ASTSignals.cpp.o
[127/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Diagnostics.cpp.o
[128/272] Building CXX object tools/clang/tools/extra/include-cleaner/lib/CMakeFiles/obj.clangIncludeCleaner.dir/WalkAST.cpp.o
[129/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FindSymbols.cpp.o
[130/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/GlobalCompilationDatabase.cpp.o
[131/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ClangdServer.cpp.o
[132/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ClangdLSPServer.cpp.o
[133/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/DumpAST.cpp.o
[134/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/AST.cpp.o
[135/272] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FindTarget.cpp.o
[136/272] Linking CXX executable bin/clang-19
[137/272] Linking CXX executable bin/clang-repl
[138/272] Linking CXX shared library lib/libclang-cpp.so.19.0git
ninja: build stopped: subcommand failed.

```

https://github.com/llvm/llvm-project/pull/91221