Remove backend tests on old inference

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

compiler/testData/codegen/box/callableReference/adaptedReferences/innerConstructorWithVararg.kt

@@ -1,6 +1,3 @@
-
-// !LANGUAGE: +NewInference +FunctionReferenceWithDefaultValueAsOtherType
-
 class Outer(val o: String) {
     inner class Inner1(val i: Int, vararg v: String) {
         val result = "I1" + o + i + if (v.size == 0) "E" else v[0]