cmake LWS_HAVE_MEMSET examples

warmcat/libwebsockets CMakeLists.txt :646 

CHECK_FUNCTION_EXISTS(memset LWS_HAVE_MEMSET)

c-jimenez/open-ocpp 3rdparty/libwebsockets/CMakeLists.txt :570 

CHECK_FUNCTION_EXISTS(memset LWS_HAVE_MEMSET)

fluffos/fluffos src/thirdparty/libwebsockets/CMakeLists.txt :553 

CHECK_FUNCTION_EXISTS(memset LWS_HAVE_MEMSET)