编译gcc9

在源代码目录中创建一个build目录，在build目录中执行下面命令：../configure --prefix=/usr/local/gcc-9.2.0 --enable-languages=c,c++ --disable-multilib --disable-gnattools --disable-target-libada --disable-target-libbhsail-rt  --disable-target-libphobos --disable-target-libbacktrace --disable-target-zlib --disable-target-libgfortran --disable-target-libgo --disable-target-libffi --disable-target-libobjc --disable-target-liboffloadmic