[CMake] CheckIncludeFile, CheckIncludeFiles, CheckIncludeFileCXX

[Pau Garcia i Quiles]

Hello,

What's the difference between CheckIncludeFile and CheckIncludeFiles ?
Implementations are slightly different but they seem to perform the
same exact check

Also, why is there a CheckIncludeFileCXX instead of just having a
language (C or CXX) parameter for CHECK_INCLUDE_FILE? I. e.
"CHECK_INCLUDE_FILE(INCLUDE VARIABLE LANGUAGE)", defaulting to C.

-- 
Pau Garcia i Quiles
http://www.elpauer.org
(Due to my workload, I may need 10 days to answer)