[clang-doc] Add start and end line numbers (#137732)
This patch adds start and end line numbers to clang-doc. Currently
clang-doc only encodes the start line numbers of records, struct, etc.
This patch adds start and end line number to clang-doc bitcode which is
passed to the generator. This will be used by the mustache backend to
generate line ranges. Based on the orginal patch in #135081.
Co-author: Paul Kirth <paulkirth@google.com>
Co-authored-by: PeterChou1 <peter.chou@mail.utoronto.ca>
