Remove outputDependsOnInput

Summary: No longer used

Reviewed By: @bertmaher

Differential Revision: D1610553
Remove NormalizedInstruction::changesPC

Summary: Nothing uses it.

Reviewed By: @swtaarrs

Differential Revision: D1610566
Remove default cases in uses of translator-instrs.h

Summary: Removing the defaults gives you a compile error when you add a new
opcode.  (Don't be alarmed about the nops in the interp one list: we skip those
first using isAlwaysNop, although we probably ought to just call an empty
emitFoo function ...)

Reviewed By: @swtaarrs

Differential Revision: D1610564