Fix tests: "infix modifier required" and "operator modifier required" errors

idea/testData/quickfix/createFromUsage/createFunction/next/createNextFromUsage1.kt

@@ -1,9 +1,9 @@
 // "Create member function 'next'" "true"
 class FooIterator<T> {
-    fun hasNext(): Boolean { return false }
+    operator fun hasNext(): Boolean { return false }
 }
 class Foo<T> {
-    fun iterator(): FooIterator<String> {
+    operator fun iterator(): FooIterator<String> {
         throw Exception("not implemented")
     }
 }

idea/testData/quickfix/createFromUsage/createFunction/next/createNextFromUsage1.kt.after

@@ -1,13 +1,13 @@
 // "Create member function 'next'" "true"
 class FooIterator<T> {
-    fun hasNext(): Boolean { return false }
+    operator fun hasNext(): Boolean { return false }
 
     operator fun next(): Int {
         throw UnsupportedOperationException("not implemented") //To change body of created functions use File | Settings | File Templates.
     }
 }
 class Foo<T> {
-    fun iterator(): FooIterator<String> {
+    operator fun iterator(): FooIterator<String> {
         throw Exception("not implemented")
     }
 }

idea/testData/quickfix/createFromUsage/createFunction/next/createNextFromUsage2.kt

@@ -1,9 +1,9 @@
 // "Create member function 'next'" "true"
 class FooIterator<T> {
-    fun hasNext(): Boolean { return false }
+    operator fun hasNext(): Boolean { return false }
 }
 class Foo<T> {
-    fun iterator(): FooIterator<T> {
+    operator fun iterator(): FooIterator<T> {
         throw Exception("not implemented")
     }
 }

idea/testData/quickfix/createFromUsage/createFunction/next/createNextFromUsage2.kt.after

@@ -1,13 +1,13 @@
 // "Create member function 'next'" "true"
 class FooIterator<T> {
-    fun hasNext(): Boolean { return false }
+    operator fun hasNext(): Boolean { return false }
 
     operator fun next(): T {
         throw UnsupportedOperationException("not implemented") //To change body of created functions use File | Settings | File Templates.
     }
 }
 class Foo<T> {
-    fun iterator(): FooIterator<T> {
+    operator fun iterator(): FooIterator<T> {
         throw Exception("not implemented")
     }
 }