gnu-linux: build gcc with -march=native -mtune=native

gnu-linux/make-zrythm-deps.sh.in

@@ -168,13 +168,13 @@ fetch "$url"
 tar xf "`basename "$url"`"
 prj_dir_name="`basename -s .tar.xz "$url"`"
 prj_build_dir_name="$prj_dir_name-build"
+export CFLAGS='-march=native -mtune=native'
+export CPPFLAGS='-march=native -mtune=native'
 pushd "$prj_dir_name"
 ./contrib/download_prerequisites
 popd
 mkdir "$prj_build_dir_name"
 pushd "$prj_build_dir_name"
-export CFLAGS='@MARCH_MTUNE@'
-export CPPFLAGS='@MARCH_MTUNE@'
 "$(pwd)"/../"$prj_dir_name"/configure --prefix="$deps_prefix" --enable-languages=c,c++,lto --disable-multilib --with-build-config=bootstrap-lto --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-libstdcxx-backtrace --enable-link-serialization=1 --enable-linker-build-id --enable-lto --enable-plugin --enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch --disable-werror
 make -j$num_cpus
 make install