Don't filter out tests for new inference

backend.native/tests/build.gradle

@@ -4076,7 +4076,6 @@ KotlinNativeTestKt.createTest(project, 'stdlibTest', KonanGTest) { task ->
             enableMultiplatform true
             extraOpts '-tr',
                     '-Xuse-experimental=kotlin.Experimental,kotlin.ExperimentalStdlibApi',
-                    '-XXLanguage:-NewInference',
                     "-friend-modules", project.rootProject.file("${project.properties['konan.home']}/klib/common/stdlib").absolutePath
             extraOpts project.globalTestArgs
         }

build-tools/src/main/groovy/org/jetbrains/kotlin/KonanTest.groovy

@@ -531,7 +531,6 @@ fun runTest() {
         if (!languageSettings.empty) {
             def settings = languageSettings.first()
             if (settings.contains('-ProperIeee754Comparisons') ||  // K/N supports only proper IEEE754 comparisons
-                    settings.contains('+NewInference') ||          // New inference is not implemented
                     settings.contains('-ReleaseCoroutines') ||     // only release coroutines
                     settings.contains('-DataClassInheritance')) {  // old behavior is not supported
                 return false