feat: implement objects moving and borrowing

exl/borrow.fzs

@@ -0,0 +1,26 @@
+class A
+{
+  uint some;
+}
+
+fn doSome(A a) A
+{
+  // NOTE: section below won't change `a.some` value
+
+  // if (a.some < 1)
+  // {
+  //   a.some = 1;
+  //   return a;
+  // }
+  a.some = 1;
+
+  return a;
+}
+
+A a = new A;
+a.some = 0;
+printline(a);
+
+a = doSome(a);
+printline(a);
+

exl/raii.fzs

@@ -0,0 +1,34 @@
+class Animal
+{
+  str type;
+  str name;
+  int age;
+
+  fn copy() Animal
+  {
+    Animal cp = new Animal;
+    cp.type = this.type;
+    cp.name = this.name;
+    cp.age = this.age;
+
+    return cp;
+  }
+}
+
+Animal a = new Animal;
+a.type = "Cow";
+a.name = "Buryatka";
+a.age = 5;
+
+Animal b = a.copy();
+a.name = "Gavryusha";
+a.age = 10;
+
+printline(a);
+printline(b);
+
+if (a.type == b.type && a.name != b.name && a.age < b.age)
+  printline("Test passed");
+else
+  printline("Test failed");
+