Two recent Rust developments have made another upload worthwhile:
- Large File Support on 32-bit
- the addition of the
i586-unknown-linux-gnutarget
The2in1 package offered here consists of an i686 host compiler runnable on and generating code for Pentium Pro class CPU's plus a set of i586 rlibs for easy cross-compilation. (Rustc 1.8.0 nightly 20160216)
The way to build it yourself on i686 should prove as easy as:
./configure --target=i586-unknown-linux-gnu (etc.)
having previously modified the i686 target to suit your needs. Just be careful about CFLAGS present in your environment as they could derail the i586 part.
The bundled cargo binary is runnable on i586, in case bootstrapping cargo on some old Pentium box becomes the next big project 
Did I mention 32-bit exa built with recent 1.8-nightlies, like this one, is finally able to handle files larger than 2GB?
Cheers!
EDIT:
I've updated the upload to include the latest LFS patch in addition to updating the previous stage0 snapshot to make it i586 aware. The 20160217 official stage0 snapshot already knows about it by default.
Building a host i586 compiler is now a simple matter of issuing:
./configure --build=i586-unknown-linux-gnu (etc., using the updated snapshot or even the latest official one, depending on Rust version and host CPU)