Remove backend tests on old inference

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

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

@@ -1,5 +1,3 @@
-// !LANGUAGE: +NewInference +FunctionReferenceWithDefaultValueAsOtherType +FunctionalInterfaceConversion +SamConversionPerArgument +SamConversionForKotlinFunctions
-
 fun interface IFoo {
     fun foo(i: Int)
 }
@@ -11,4 +9,3 @@ fun withVararg(vararg xs: Int) = 42
 fun test() {
     useFoo(::withVararg)
 }
-