cmake HAS_C11 examples

erthink/libmdbx CMakeLists.txt :550 

list(FIND CMAKE_C_COMPILE_FEATURES c_std_11 HAS_C11)

erthink/libmdbx CMakeLists.txt :568 

elseif(
    HAS_C11 LESS 0
    AND NOT C_FALLBACK_GNU11
    AND NOT C_FALLBACK_11)

erthink/libmdbx cmake/compiler.cmake :423 

list(FIND CMAKE_C_COMPILE_FEATURES c_std_11 HAS_C11)