naive: support loong64 build

tested with ../tests/basic.sh out/Release/naive. base changes come from chromium loong's official patch: https://github.com/loongson/chromium/blob/loongarch-patches/chromium120/new-world/0001-CH120-new-world-Add-llvm-cross-build-support-for-loo.patch Using the tarball from https://github.com/loongson/build-tools/releases instead of debian (which just accept loongarch64 as its port) and the debian sysroot support might be very new https://wiki.debian.org/Ports/loong64 (I didn't have a change to see it).