LLVM build failures

Hi,

(2) on alpha, gcc 4.2.4. The "unknown component name: alphacodegen"
didn't use to occur.

My fault, I'll fix it. The problem is that lli wants to link in JIT
module, which does not exist for these targets.

JIT use to exist (and sometimes work) for alpha. I haven't done
anything to get rid of it so I'm assuming it isn't being registered
properly or something due to me not having done anything to keep it
working.

Andrew