Break / continue implementation, test with break / continue, related changes in loop & loop tests

compiler/testData/ir/irCfg/loop/isPerfect.kt

@@ -0,0 +1,9 @@
+fun isPerfect(n: Int): Boolean {
+    var sum = 1
+    for (m in 2..n/2) {
+        if (n % m > 0) continue
+        sum += m
+        if (sum > n) break
+    }
+    return sum == n
+}