feat: implement math in vm

include/compiler/utils/fzl_const_pool.h

@@ -8,7 +8,8 @@
 // Constant types
 typedef enum
 {
-  FZL_CONSTTYPE_STRING
+  FZL_CONSTTYPE_STRING,
+  FZL_CONSTTYPE_NUMBER
 } fzl_consttype_t;
 
 // Constant descriptor
@@ -23,6 +24,11 @@ typedef struct
       const char *chars;
       size_t length;
     } string;
+
+    struct
+    {
+      uint64_t value;
+    } num;
   } as;
 } fzl_const_t;