KT-12985 Do not create range instances for 'for' loop in CharSequence.indices

compiler/testData/codegen/box/ranges/forInIndices/forInCharSequenceIndices.kt

@@ -0,0 +1,16 @@
+// WITH_RUNTIME
+
+fun test(s: CharSequence): Int {
+    var result = 0
+    for (i in s.indices) {
+        result = result * 10 + (i + 1)
+    }
+    return result
+}
+
+fun box(): String {
+    val test = test("abcd")
+    if (test != 1234) return "Fail: $test"
+
+    return "OK"
+}