cmake BOOST_COBALT_HAS_COROUTINE_INCLUDE examples

Jackarain/proxy third_party/boost/libs/cobalt/cmake/CheckRequirements.cmake :19 

try_compile(
        BOOST_COBALT_HAS_COROUTINE_INCLUDE
        ${CMAKE_CURRENT_BINARY_DIR}
        ${CMAKE_CURRENT_LIST_DIR}/coroutine.cpp
        CXX_STANDARD 20
        CXX_STANDARD_REQUIRED 20
        OUTPUT_VARIABLE TRY_COMPILE_OUTPUT)