Author :
Azat Khuzhin
Date :
2017-01-30 03:17:41
Hash :fa135bdc Message :cmake: Fix checking of enum values from sysctl.h
CheckSymbolExists do not do this, so add new CheckConstExists that will
use CheckCSourceCompiles() to check this.
v2: use set() instead of string(APPEND)
Azat Khuzhin