[Test] Add debug names to unnamed test disposables

- This helps to track down disposables which are never disposed, and
  reduces confusion when printing disposables in general (the names will
  now be meaningful, instead of endless lists of "newDisposable" and
  "TestDisposable").

^KT-64099

native/objcexport-header-generator/src/test/kotlin/org/jetbrains/kotlin/backend/konan/testUtils/AbstractObjCExportHeaderGeneratorTest.kt

@@ -20,7 +20,7 @@ abstract class AbstractObjCExportHeaderGeneratorTest(
         fun generateHeaders(disposable: Disposable, root: File): String
     }
 
-    private val testRootDisposable = Disposer.newDisposable()
+    private val testRootDisposable = Disposer.newDisposable("${AbstractObjCExportHeaderGeneratorTest::class.simpleName}.testRootDisposable")
     protected val objCExportTestDataDir = testDataDir.resolve("objcexport")
 
     @After

native/objcexport-header-generator/src/test/kotlin/org/jetbrains/kotlin/backend/konan/tests/ObjCExportMapperTest.kt

@@ -31,7 +31,7 @@ import kotlin.test.assertNull
  * The test also acts as quick entry point for debugging the [ObjCExportMapper]
  */
 class ObjCExportMapperTest : InlineSourceTestEnvironment {
-    override val testDisposable = Disposer.newDisposable()
+    override val testDisposable = Disposer.newDisposable("${ObjCExportMapperTest::class.simpleName}.testDisposable")
     override val kotlinCoreEnvironment: KotlinCoreEnvironment = createKotlinCoreEnvironment(testDisposable)
 
     @TempDir

native/objcexport-header-generator/src/test/kotlin/org/jetbrains/kotlin/backend/konan/tests/ObjCExportNamerTest.kt

@@ -35,7 +35,7 @@ import kotlin.test.assertEquals
  */
 class ObjCExportNamerTest : InlineSourceTestEnvironment {
 
-    override val testDisposable = Disposer.newDisposable()
+    override val testDisposable = Disposer.newDisposable("${ObjCExportNamerTest::class.simpleName}.testDisposable")
 
     override val kotlinCoreEnvironment = createKotlinCoreEnvironment(testDisposable)