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

idea/testData/intentions/simplifyNegatedBinaryExpression/in.kt

@@ -1,6 +1,6 @@
 // INTENTION_TEXT: Simplify negated 'in' expression to '!in'
 class A(val e: Int) {
-    fun contains(i: Int): Boolean = e == i
+    operator fun contains(i: Int): Boolean = e == i
 }
 
 fun test(n: Int) {

idea/testData/intentions/simplifyNegatedBinaryExpression/in.kt.after

@@ -1,6 +1,6 @@
 // INTENTION_TEXT: Simplify negated 'in' expression to '!in'
 class A(val e: Int) {
-    fun contains(i: Int): Boolean = e == i
+    operator fun contains(i: Int): Boolean = e == i
 }
 
 fun test(n: Int) {

idea/testData/intentions/simplifyNegatedBinaryExpression/inapplicableBinaryOperation.kt

@@ -1,5 +1,5 @@
 // IS_APPLICABLE: false
-fun Int.lt(b: Int): Boolean = this < b
+infix fun Int.lt(b: Int): Boolean = this < b
 fun test(n: Int) {
     <caret>!(1 lt 2)
 }

idea/testData/intentions/simplifyNegatedBinaryExpression/notIn.kt

@@ -1,6 +1,6 @@
 // INTENTION_TEXT: Simplify negated '!in' expression to 'in'
 class A(val e: Int) {
-    fun contains(i: Int): Boolean = e == i
+    operator fun contains(i: Int): Boolean = e == i
 }
 
 fun test(n: Int) {

idea/testData/intentions/simplifyNegatedBinaryExpression/notIn.kt.after

@@ -1,6 +1,6 @@
 // INTENTION_TEXT: Simplify negated '!in' expression to 'in'
 class A(val e: Int) {
-    fun contains(i: Int): Boolean = e == i
+    operator fun contains(i: Int): Boolean = e == i
 }
 
 fun test(n: Int) {