Remove backend tests on old inference

Also remove any mentions of NewInference, and rename some tests.

compiler/testData/ir/irText/expressions/callableReferences/withArgumentAdaptationAndReceiver.kt

@@ -1,5 +1,3 @@
-// !LANGUAGE: +NewInference, +FunctionReferenceWithDefaultValueAsOtherType
-
 fun use(fn: (Int) -> Unit) { fn(1) }
 
 class Host {
@@ -26,4 +24,4 @@ class Host {
     fun testBoundReceiverExpression() {
         use(Host()::withVararg)
     }
-}
+}