arm-none-eabi-gcc build from source with --enable-threads

Question

I am trying to use the arm-none-eabi-gcc and enable the std::mutex and other Thread support on it. I tried to re-compile the compiler from source as I found the source code from here

However, I am failing to enable it. Is there any possible way to build it with Thread:posix support enabled?

What have I tried?

1. Downloaded the source code.
2. Opened the build-toolchain.sh script and changed all the --disable-threads to --enable-threads
3. Ran the commands as stated in the How-to-build-toolchain.pdf file and the build finished with error however there is a install_native folder that is created and when I went into it and ran "arm-none-eabi-gcc -v" It still gave Thread:single as the output.

Where am I doing wrong?