[Decompiler] Fix printing of lets (#314)

* fix let prints and windows warnings

* missing include for windows

* windows again

decompiler/Disasm/Instruction.cpp

@@ -153,6 +153,7 @@ bool InstructionAtom::operator==(const InstructionAtom& other) const {
       return true;
     default:
       assert(false);
+      return false;
   }
 }