有时候要用到比较新的gcc 而centos6的gcc有时不够新，例如编译安装nodejs就不够了，于是
tar xvf gcc-5.3.0.tar.bz2 && cd gcc-5.3.0
./contrib/download_prerequisites
cd ..
mkdir gcc-build && cd gcc-build
../gcc-5.3.0/configure --enable-checking=release --enable-languages=c,c++ --disable-multilib && make -j2 && make install
node: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.15′ not found
cd gcc-build/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs
#strings libstdc++.so.6.0.21 | grep GLIBCXX
#把libstdc++.so.6.0.21拷贝到 /usr/lib64的目录
cp libstdc++.so.6.0.21 /usr/lib64
cd /usr/lib64/ && mv libstdc++.so.6 libstdc++.so.6bak
ln -s libstdc++.so.6.0.21 libstdc++.so.6
