Fix compiler tests

compiler/testData/diagnostics/tests/inference/regressions/kt1718.kt

@@ -14,4 +14,4 @@ fun test() {
 
 //from library
 fun arrayList<T>(vararg <!UNUSED_PARAMETER!>values<!>: T) : ArrayList<T> {<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>
-fun <T> Iterable<T>.plus(<!UNUSED_PARAMETER!>elements<!>: Iterable<T>): List<T> {<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>
+operator fun <T> Iterable<T>.plus(<!UNUSED_PARAMETER!>elements<!>: Iterable<T>): List<T> {<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>

compiler/testData/diagnostics/tests/inference/regressions/kt1718.txt

@@ -3,5 +3,5 @@ package
 package n {
     public fun </*0*/ T> arrayList(/*0*/ vararg values: T /*kotlin.Array<out T>*/): java.util.ArrayList<T>
     public fun test(): kotlin.Unit
-    public fun </*0*/ T> kotlin.Iterable<T>.plus(/*0*/ elements: kotlin.Iterable<T>): kotlin.List<T>
+    public operator fun </*0*/ T> kotlin.Iterable<T>.plus(/*0*/ elements: kotlin.Iterable<T>): kotlin.List<T>
 }

compiler/testData/diagnostics/tests/inference/regressions/kt3496.kt

@@ -5,5 +5,5 @@ class B<T> {
     fun <S> x (y: B<Iterable<S>>) {
         val z: S = y[""] // does not work with [], but works with .get()
     }
-    fun <S> get(s : String): S = throw Exception()
+    operator fun <S> get(s : String): S = throw Exception()
 }

compiler/testData/diagnostics/tests/inference/regressions/kt3496.txt

@@ -3,7 +3,7 @@ package
 public final class B</*0*/ T> {
     public constructor B</*0*/ T>()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    public final fun </*0*/ S> get(/*0*/ s: kotlin.String): S
+    public final operator fun </*0*/ S> get(/*0*/ s: kotlin.String): S
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
     public final fun </*0*/ S> x(/*0*/ y: B<kotlin.Iterable<S>>): kotlin.Unit

compiler/testData/diagnostics/tests/inference/regressions/kt3496_2.kt

@@ -8,4 +8,4 @@ class F<T> {
         val z: ArrayList<T> = y["", w]
     }
 }
-fun <V, T> Any.get(s: String, w: ArrayList<V>): ArrayList<T> = throw Exception()
+operator fun <V, T> Any.get(s: String, w: ArrayList<V>): ArrayList<T> = throw Exception()

compiler/testData/diagnostics/tests/inference/regressions/kt3496_2.txt

@@ -1,6 +1,6 @@
 package
 
-public fun </*0*/ V, /*1*/ T> kotlin.Any.get(/*0*/ s: kotlin.String, /*1*/ w: java.util.ArrayList<V>): java.util.ArrayList<T>
+public operator fun </*0*/ V, /*1*/ T> kotlin.Any.get(/*0*/ s: kotlin.String, /*1*/ w: java.util.ArrayList<V>): java.util.ArrayList<T>
 
 public final class F</*0*/ T> {
     public constructor F</*0*/ T>()