Finish up parser and assembler with more-or-less complete syntax

Major changes inlude:

* Bit the bullet and now instructions have their length hard-coded
* Move from_utf8 object parsing to be done by their objects (instead of
  a Parser god object)
* A list of AST sections are assembled into an Object using the new
  vm::obj::assemble module.
* Changed the object layout some in the spec, and adjusted code to match
  this.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

src/main.rs

@@ -5,6 +5,7 @@ mod common;
 mod vm;
 
 use std::{
+    convert::TryFrom,
     io::{self, Read},
     process,
 };
@@ -18,15 +19,16 @@ fn get_input_string() -> io::Result<String> {
 }
 
 fn main() -> Result<()> {
-    use vm::syn::parser::ProgramParser;
+    use vm::obj::syn::parser::SectionsParser;
     let contents = get_input_string()?;
-    let ast = match ProgramParser::new().parse(&contents) {
+    let ast = match SectionsParser::new().parse(&contents) {
         Ok(ast) => ast,
         Err(err) => {
             eprintln!("{}", err);
             process::exit(1);
         },
     };
-    println!("{:#?}", ast);
+    let obj = vm::obj::obj::Object::try_from(&ast)?;
+    println!("{:#?}", obj);
     Ok(())
 }