cmake file(HASH) examples

rui314/mold lib/update-git-hash.cmake :4 

file(READ "${SOURCE_DIR}/.git/HEAD" HASH)

rui314/mold lib/update-git-hash.cmake :10 

file(READ "${SOURCE_DIR}/.git/${HEAD}" HASH)

microsoft/vcpkg scripts/detect_compiler/CMakeLists.txt :37 

file(SHA1 "${compiler_path}" HASH)

xournalpp/xournalpp cmake/include/Version.cmake :77 

file(STRINGS ${CMAKE_SOURCE_DIR}/VERSION HASH LIMIT_INPUT 16)