Move JvmRuntimeDescriptorLoaderTest to core/descriptors.runtime/tests

This allows to get rid of the dependency on descriptors.runtime from
compiler/IDE tests which is problematic: classes there clash with the
classes in kotlin-reflect, which reference declarations in shadowed
packages

core/descriptors.runtime/build.gradle.kts

@@ -1,20 +1,33 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
 apply { plugin("kotlin") }
 
-jvmTarget = "1.6"
-javaHome = rootProject.extra["JDK_16"] as String
-
 dependencies {
-    compile(project(":core:util.runtime"))
-    compile(project(":core:descriptors"))
-    compile(project(":core:descriptors.jvm"))
+    compileOnly(project(":core:util.runtime"))
+    compileOnly(project(":core:descriptors"))
+    compileOnly(project(":core:descriptors.jvm"))
+
+    testCompile(projectTests(":compiler:tests-common"))
+    testCompile(projectTests(":generators:test-generator"))
 }
 
 sourceSets {
     "main" { projectDefault() }
-    "test" {}
+    "test" { projectDefault() }
 }
 
-tasks.withType<JavaCompile> {
+val compileJava by tasks.getting(JavaCompile::class) {
     sourceCompatibility = "1.6"
     targetCompatibility = "1.6"
 }
+
+val compileKotlin by tasks.getting(KotlinCompile::class) {
+    kotlinOptions.jvmTarget = "1.6"
+    kotlinOptions.jdkHome = rootProject.extra["JDK_16"] as String
+}
+
+val generateTests by generator("org.jetbrains.kotlin.generators.tests.GenerateRuntimeDescriptorTestsKt")
+
+projectTest {
+    workingDir = rootDir
+}