Update/add instructions in parser

* StoreImm just uses a u64 instead of u32 - we'll figure out the layout
  later
* Jmp implementation added (can't believe I forgot this)
* Add Inst AST item, whose immediates don't have to be a u64 right away

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

src/vm/vm.rs

@@ -190,6 +190,10 @@ impl Vm {
                     self.remove_flags(Flags::COMPARE);
                 }
             }
+            Inst::Jmp(r1) => {
+                let w1 = self.get_reg(r1);
+                self.set_reg(IP, w1);
+            }
             Inst::Jz(r1) => {
                 if !self.flags().contains(Flags::COMPARE) {
                     let w1 = self.get_reg(r1);