This diff removes the Marker opcode, replacing it with a BCMarker
struct in each IRInstruction. This gives us fewer redundant lines in IRTrace
dumps and allows for more straightforward control of which IRInstructions are
associated with which bytecodes. I took this opportunity to do some more
cleanup of ir dumps as well, and it's now possible to interpOne every codegen
punt.
In some circumstances we create unreachable blocks,
making the assert invalid. Currently nothing depends on the
assert being true, so remove it for now.
For converting Transl -> JIT. We either do this or convert all the other `Trace` calls to `HPHP::Trace` which seemed worse. This also niecly mirrors `IRInstruction`.