Update examples to new assembly syntax

examples/stack.mimasm

@@ -12,27 +12,27 @@
 ; Functions take a fixed number of arguments. For this example, all
 ; values have a size of one word (24 bit).
 
-IAR = main
-SP = 0xfffff
-FP = 0xfffff
+.reg IAR main
+.reg SP -1
+.reg FP -1
 
 ; Temporary variables at a fixed memory location
 ;
 ; These are useful for commands like ADD, which need a fixed memory
 ; address. They are always under the complete control of the currently
 ; running function.
-tmp1: LIT 0
-tmp2: LIT 0
-tmp3: LIT 0
-tmp4: LIT 0
-tmp5: LIT 0
+tmp1: .lit 0
+tmp2: .lit 0
+tmp3: .lit 0
+tmp4: .lit 0
+tmp5: .lit 0
 
-100:
+.org 100
 main:
   CALL caller
   HALT
 
-200:
+.org 200
 caller:
   ;; 1. Initialisation
 
@@ -121,7 +121,7 @@ caller:
   
   RET
 
-300:
+.org 300
 callee:
   ; This callee doesn't really need its own stack since all
   ; calculations did fit into the temporary variables. I still created