There's no real reason (other than historical) why code in llc should be
kept as c++ code. Let's rewrite it as C so that it can be included by
existing C code without having to add C->C++ shim, ifdefs all around,
etc.
This simplifies code and easies modification/improvement of the related
objects.
Change-Id: I250680ba581167d7398b2f734769c756cbb61c48