Add tests for equals, hashCode, toString in String and Number

compiler/testData/codegen/box/primitiveTypes/numberEqualsHashCodeToString.kt

@@ -0,0 +1,17 @@
+fun test(n: Number) {
+    if (!n.equals(n)) throw Error("fail 1 for $n")
+    if (n.equals(1)) throw Error("fail 2 for $n")
+    if (n.equals(1L)) throw Error("fail 3 for $n")
+    if (n != n) throw Error("fail 4 for $n")
+    if (n == 1) throw Error("fail 5 for $n")
+    if (n == 1L) throw Error("fail 6 for $n")
+    if (n.hashCode() != n.toInt()) throw Error("fail 7 for $n")
+    if (n.toString() != "$n") throw Error("fail 8 for $n")
+}
+
+fun box(): String {
+    test(234)
+    test(546L)
+
+    return "OK"
+}

compiler/testData/codegen/box/primitiveTypes/stringEqualsHashCodeToString.kt

@@ -0,0 +1,13 @@
+fun test(s: String) {
+    if (!s.equals(s)) throw Error("fail 1 for $s")
+    if (s.equals(1)) throw Error("fail 2 for $s")
+    if (s != s) throw Error("fail 4 for $s")
+    if (s == "111") throw Error("fail 5 for $s")
+    if (s.hashCode() != -1268878963) throw Error("fail 7 for $s")
+    if (s.toString() != "$s") throw Error("fail 8 for $s")
+}
+
+fun box(): String {
+    test("foobar")
+    return "OK"
+}