Installing multilib on x86_64*-linux* with 32-bit libs to lib32 and 64-bit libs to lib

[Albert Chin <gcc-help@xxxxxxxxxxxxxxxxxxxxxxxxx>]

How do I build gcc-4.0.2 on x86_64*-linux* so 32-bit libs are
installed to $prefix/lib32 and 64-bit libs to $prefix/lib?

-- 
albert chin (china@xxxxxxxxxxxxxxxxxx)