This is a partial step towards merging the HPHP::VM namespace
up into its parent. To keep it reviewable/mergeable I'm not doing
everything at once here, but most of the code I've touched seems
improved. I've drawn an invisible line around the jit, Unit and
its cohort (Class, Func, PreClass, etc.); we'll get back to them
soon.
This diff adds full support for doing general interpOnes in HHIR.
Whenever a bytecode instruction fails (punts) in the HHBC->HHIR
translation, the NormalizedInstruction is marked with an 'interp' flag
and the HHIR translation for the whole tracelet is retried. This
forces an InterpOne of such instruction, preventing HHIR from
attempting to translate it again, which then allows the HHBC->HHIR
translation to make further progress. If another instruction in the
sequence punts again, the process is repeat and so on.
This change is mostly for FB internal organizational reasons.
Building is not effected beyond the fact that the target now
lands in hphp/hhvm/hhvm rather than src/hhvm/hhvm.
Keith Adams