added tests for break and continue

lox.t/continue/for.lox

@@ -0,0 +1,16 @@
+for (var i = 0; i < 10; i = i + 1) {
+    if (i == 5)
+        continue;
+
+    print i;
+}
+// expect: 0
+// expect: 1
+// expect: 2
+// expect: 3
+// expect: 4
+// expect: 6
+// expect: 7
+// expect: 8
+// expect: 9
+

lox.t/continue/outside_loop.lox

@@ -0,0 +1,2 @@
+continue;
+// expect: error

lox.t/continue/while.lox

@@ -0,0 +1,21 @@
+var i = 0;
+
+while (i < 10) {    
+    if (i == 5) {
+        i = i + 1;
+        continue;
+    }
+
+    print i;
+    
+    i = i + 1;
+}
+// expect: 0
+// expect: 1
+// expect: 2
+// expect: 3
+// expect: 4
+// expect: 6
+// expect: 7
+// expect: 8
+// expect: 9