[KLIB IC] Produce .klib file instead of directory in test

- disable sourcemaps
 - clean up comment

compiler/incremental-compilation-impl/test/org/jetbrains/kotlin/incremental/AbstractIncrementalJsKlibCompilerRunnerTest.kt

@@ -2,16 +2,17 @@ package org.jetbrains.kotlin.incremental
 
 import org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments
 import org.jetbrains.kotlin.incremental.testingUtils.BuildLogFinder
+import org.jetbrains.kotlin.library.KLIB_FILE_EXTENSION
 import java.io.File
 
 abstract class AbstractIncrementalJsKlibCompilerRunnerTest : AbstractIncrementalJsCompilerRunnerTest() {
     override fun createCompilerArguments(destinationDir: File, testDir: File): K2JSCompilerArguments =
         K2JSCompilerArguments().apply {
             libraries = "build/js-ir-runtime/full-runtime.klib"
-            outputFile = File(destinationDir, "${testDir.name}.klib").path
-            sourceMap = true
-            // Don't zip klib content since date on files affect the md5 checksum we compute to check whether output files identical
-            irProduceKlibDir = true
+            outputFile = File(destinationDir, "${testDir.name}.$KLIB_FILE_EXTENSION").path
+            sourceMap = false
+            irProduceKlibDir = false
+            irProduceKlibFile = true
             irOnly = true
         }