Good point on the documentation. I'll make the changes.

As for the test error on clang for ia32, hopefully that won't hold up this
PR. I'll open a bug and begin investing ASAP. So far I've asked on the llvm
irc, but no one knew why.

Is there official documentation on which compilers are supported, and at
what versions? With a problem like this it seems like all tests would need
to be run in x64 and ia32 builds of clang, gcc and msvc. (just saying since
wouldn't have thought only one compiler on one architecture would fail)