32-bit build of GCC 6

Over on http://gnuarmeclipse.github.io/toolchain/install/, I see this:

starting with version 6.x, GNU/Linux toolchains are 64-bits applications, and should work directly on most modern distributions;

Is this a project choice for the GNU ARM Embedded project, or is it something that's mandated by the toolchain trunk? In other words, is it still possible to build a 32-bit version from the sources? If so, any advice?

Thanks,

steve