tests: add tests for continue/break in last statement of an `or{}`

vlib/v/tests/option_in_loop_test.v

@@ -0,0 +1,36 @@
+fn opt_0_10_20(x int) ?int {
+	if x < 0 || (x >= 10 && x <= 20) {
+		return error('invalid')
+	}
+	return x
+}
+
+fn test_options_in_for_loop_break() {
+	mut sum := 0
+	mut nbreaks := 0
+	for i := 5; i < 15; i++ {
+		x := opt_0_10_20(i) or {
+			nbreaks++
+			break
+		}
+		sum += x
+		// println('i: ${i:3} | sum: ${sum:3}')
+	}
+	assert nbreaks == 1
+	assert sum == 35
+}
+
+fn test_options_in_for_loop_continue() {
+	mut sum := 0
+	mut ncontinue := 0
+	for i := -5; i < 30; i++ {
+		x := opt_0_10_20(i) or {
+			ncontinue++
+			continue
+		}
+		sum += x
+		// println('i: ${i:3} | sum: ${sum:3}')
+	}
+	assert ncontinue == 16
+	assert sum == 270
+}