[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 `llvm-clang-aarch64-darwin` running on `doug-worker-5` while building `clang` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/623

Here is the relevant piece of the build log for the reference:
```
Step 5 (build-unified-tree) failure: build (failure)
...
90.694 [1676/8/4110] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FeatureModule.cpp.o
90.715 [1675/8/4111] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Feature.cpp.o
91.958 [1674/8/4112] Building CXX object tools/clang/tools/extra/include-cleaner/unittests/CMakeFiles/ClangIncludeCleanerTests.dir/FindHeadersTest.cpp.o
92.458 [1673/8/4113] Linking CXX executable tools/clang/tools/extra/include-cleaner/unittests/ClangIncludeCleanerTests
92.529 [1672/8/4114] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ClangdServer.cpp.o
92.549 [1671/8/4115] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FileDistance.cpp.o
93.641 [1670/8/4116] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/AST.cpp.o
93.670 [1669/8/4117] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FS.cpp.o
93.693 [1668/8/4118] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FuzzyMatch.cpp.o
94.142 [1667/8/4119] 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 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /opt/homebrew/bin/ccache /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/clangd -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/clangd -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/clangd/../include-cleaner/include -I/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/clangd/../clang-tidy -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/include -I/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/include -I/Users/buildbot/buildbot-root/aarch64-darwin/build/include -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/include -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/pseudo/lib/../include -isystem /opt/homebrew/include -fPIC -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 -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG -std=c++17 -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX14.4.sdk  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -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 /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/clangd/Format.cpp
/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/clangd/Format.cpp:284:11: error: no member named 'KeepEmptyLinesAtTheStartOfBlocks' in 'clang::format::FormatStyle'
    Style.KeepEmptyLinesAtTheStartOfBlocks = true;
    ~~~~~ ^
1 error generated.
94.448 [1667/7/4120] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/CodeComplete.cpp.o
94.493 [1667/6/4121] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/Diagnostics.cpp.o
95.326 [1667/5/4122] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ClangdLSPServer.cpp.o
96.028 [1667/4/4123] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FindSymbols.cpp.o
97.361 [1667/3/4124] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/GlobalCompilationDatabase.cpp.o
98.256 [1667/2/4125] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/DumpAST.cpp.o
100.241 [1667/1/4126] Building CXX object tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/FindTarget.cpp.o
ninja: build stopped: subcommand failed.

```

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