[Courgette] Refactor: Add and use Instruction*Receptor classes; call ParseFile() in 2 passes.

courgette/disassembler_win32_x64.h

Index: courgette/disassembler_win32_x64.h
diff --git a/courgette/disassembler_win32_x64.h b/courgette/disassembler_win32_x64.h
index 8a0f6f8c7ecd5fa5dfaba5fc7d0c3a406bd91128..7c0ac010b81d0bdbbb2a77cc16bea682472556ac 100644
--- a/courgette/disassembler_win32_x64.h
+++ b/courgette/disassembler_win32_x64.h
@@ -16,6 +16,7 @@
 namespace courgette {
 
 class AssemblyProgram;
+class InstructionReceptor;
 
 class DisassemblerWin32X64 : public DisassemblerWin32 {
  public:
@@ -37,10 +38,10 @@ class DisassemblerWin32X64 : public DisassemblerWin32 {
   RVA Address64ToRVA(uint64_t address) const;
 
  protected:
-  // Disassembler interfaces.
+  // DisassemblerWin32 interfaces.
   void ParseRel32RelocsFromSection(const Section* section) override;
   int AbsVAWidth() const override { return 8; }
-  CheckBool EmitAbs(Label* label, AssemblyProgram* program) override;
+  CheckBool EmitAbs(Label* label, InstructionReceptor* receptor) const override;
   bool SupportsRelTableType(int type) const override {
     return type == 10;  // IMAGE_REL_BASED_DIR64
   }