Attempt to fix ABI tests on TC

Locally they work fine

plugins/jvm-abi-gen/build.gradle.kts

@@ -20,6 +20,7 @@ dependencies {
     testCompile(commonDep("junit:junit"))
     testCompile(projectTests(":compiler:tests-common"))
     testCompile(projectTests(":compiler:incremental-compilation-impl"))
+    testRuntime(intellijCoreDep())
 }
 
 sourceSets {

plugins/jvm-abi-gen/test/org/jetbrains/kotlin/jvm/abi/BaseJvmAbiTest.kt

@@ -5,7 +5,6 @@
 
 package org.jetbrains.kotlin.jvm.abi
 
-import com.intellij.testFramework.UsefulTestCase
 import junit.framework.TestCase
 import org.jetbrains.kotlin.cli.common.ExitCode
 import org.jetbrains.kotlin.cli.jvm.K2JVMCompiler
@@ -74,6 +73,6 @@ abstract class BaseJvmAbiTest : TestCase() {
     }
 
     protected val kotlinJvmStdlib = File("dist/kotlinc/lib/kotlin-stdlib.jar").also {
-        UsefulTestCase.assertExists(it)
+        check(it.exists()) { "Stdlib file '$it' does not exist" }
     }
 }