add existing documentation

doc/vm-instructions.txt

@@ -0,0 +1,48 @@
+ldr	<dest:REG>	<src:SP-offset>
+ldr	<dest:REG>	<src:BP-offset>
+ldr	<dest:REG>	<src:SELF-offset>
+ldr	<dest:REG>	<src:SELF-offset>
+ldr	<dest:REG>	<src:IMM>
+ldr	<dest:REG>	<src:POOL_INDEX>
+
+str	<src:REG>	<dest:SP-offset>
+str	<src:REG>	<dest:BP-offset>
+str	<src:REG>	<dest:SELF-offset>
+
+push	<value:REG>
+pop	<dest:REG>
+
+add	<dest:REG>	<value1:REG> 	<value2:REG>
+sub	<dest:REG>	<value1:REG> 	<value2:REG>
+mul	<dest:REG>	<value1:REG> 	<value2:REG>
+div	<dest:REG>	<value1:REG> 	<value2:REG>
+
+cmp	<value1:REG>	<value2:REG>
+
+c.eq	<dest:REG>	<value1:REG> 	<value2:REG>
+c.ne	<dest:REG>	<value1:REG>	<value2:REG>
+c.lt	<dest:REG>	<value1:REG>	<value2:REG>
+c.le	<dest:REG>	<value1:REG>	<value2:REG>
+c.gt	<dest:REG>	<value1:REG>	<value2:REG>
+c.ge	<dest:REG>	<value1:REG>	<value2:REG>
+
+br	<dest:IMM>
+b.z	<dest:IMM>
+b.nz	<dest:IMM>
+b.eq	<dest:IMM>
+b.ne	<dest:IMM>
+b.lt	<dest:IMM>
+b.le	<dest:IMM>
+b.gt	<dest:IMM>
+b.ge	<dest:IMM>
+
+ob.c	<dest:REG>	<class:POOL_INDEX>
+ob.e	<ref:REG>
+
+lam.c	<dest:REG>	<body:POOL_INDEX>
+
+it.g	<dest:REG>	<iterator:REG>
+it.n	<iterator:REG>
+it.v	<iterator:REG>
+
+ret