build: Add -Wno-class-memaccess on linux if building with g++ >= 8
build: Add -Wno-class-memaccess on linux if building with g++ >= 8

mstorsjo/openh264,cisco/openh264,GuangweiWang/openh264,cisco/openh264,GuangweiWang/openh264,cisco/openh264,GuangweiWang/openh264,GuangweiWang/openh264,GuangweiWang/openh264,cisco/openh264,mstorsjo/openh264,cisco/openh264,mstorsjo/openh264,GuangweiWang/openh264,cisco/openh264,mstorsjo/openh264,cisco/openh264,mstorsjo/openh264,mstorsjo/openh264,GuangweiWang/openh264,mstorsjo/openh264