This is the main CL of the AssemblyProgram reduction effort, which makes
Disassembler emit instructions directly to EncodedProgram, and bypass
AssemblyProgram, which becomes a holder of LabelManager and Label
Annotation. Another big change is that Disassembler usage is exposed to
high-level flows (rather than having it hidden inside
ParseDetectedExecutable*()). Details:

- Remove ParseDetectedExecutable*() and expose DetectDisassembler().
- AssemblyProgram: Remove:
  - Entire Instruction class hierarchy.
  - Allocated instruction in the heap (including preallocated DEFBYTE
    instances).
  - enum OP {}, which duplicates EncodedProgram::OP.
  - InstructionVector of pointers, which takes 100's of MB on disk.
  - Encode() interface.
- AssemblyProgram: Add:
  - AnnotateLabels() to generate Label Annotation directly from a
    generator (injected by Disassembler), using LabelReceptor template
    class for counting and stor...