Output informational message when NO_AVX512 got set

cmake/system_check.cmake

@@ -126,6 +126,7 @@ if (NOT NO_AVX512)
 execute_process(COMMAND ${CMAKE_C_COMPILER} -march=skylake-avx512 -c -v -o ${PROJECT_BINARY_DIR}/avx512.o ${PROJECT_BINARY_DIR}/avx512.c OUTPUT_QUIET ERROR_QUIET RESULT_VARIABLE NO_AVX512)
 if (NO_AVX512 EQUAL 1)
 set (CCOMMON_OPT "${CCOMMON_OPT} -DNO_AVX512")
+message(STATUS "Disabling AVX512 support as your compiler toolchain cannot handle AVX512 instructions.")
 endif()
   file(REMOVE "avx512.c" "avx512.o")
 endif()