Use a state machine for tracking SPIR-V sections and add nops to pad
Use a state machine for tracking SPIR-V sections and add nops to pad

* We want to make sure every section always has at least one word in it
  so we can unambiguously tell which section we're appending to. If the
  debug section is empty, it's hard to tell the difference between
  appending to the entry point section and inserting into the debug
  section, so we add a nop that will get stripped out later.

googlestadia/renderdoc,etnlGD/renderdoc,TurtleRockStudios/renderdoc_public,Zorro666/renderdoc,etnlGD/renderdoc,googlestadia/renderdoc,baldurk/renderdoc,Zorro666/renderdoc,etnlGD/renderdoc,etnlGD/renderdoc,michaelrgb/renderdoc,TurtleRockStudios/renderdoc_public,baldurk/renderdoc,michaelrgb/renderdoc,etnlGD/renderdoc,TurtleRockStudios/renderdoc_public,Zorro666/renderdoc,michaelrgb/renderdoc,michaelrgb/renderdoc,googlestadia/renderdoc,baldurk/renderdoc,baldurk/renderdoc,baldurk/renderdoc,Zorro666/renderdoc,michaelrgb/renderdoc,googlestadia/renderdoc,TurtleRockStudios/renderdoc_public,etnlGD/renderdoc,baldurk/renderdoc,googlestadia/renderdoc,googlestadia/renderdoc,Zorro666/renderdoc,TurtleRockStudios/renderdoc_public,TurtleRockStudios/renderdoc_public,Zorro666/renderdoc