This adds a new profiling mode for vector instruction
shapes. I'm planning on using this to identify any common cases that
may be worth special casing, like we do for simple SetM, CGetM, and
IssetM instructions. Instead of adding Yet Another Hashtable Stats
Map, I created a generic version and changed TRACE=punt:1 to use it as
well.
I also changed emitInterpOneOrPunt to use a more specific name.
bsimmers
b8ebb48421