Format.h is used to generate ClangFormatStyleOptions.rst, the layout of the comments is critical to the rst file. Accidentally clang-formatting Format.h can lead to the .rst changing.
This revision simply add // clang-format off/on statement around the areas who formatting needs to be maintained, mainly around the options that are related to what happens when the line breaks due to ColumnLimit (which is what is happening to the comment)
This allows Format.h to be clang-formatted without causing a change in the documentation when dump_format_style.py is rerun, which is also part of the revision.
Can this documentation be formatted in a way that avoids clang-format reformatting it? It doesn't look like it depends on long lines like the other bits in this change.