KT-24353 Include kotlin-test-junit5 into coreLibraries, use JDK_18 to build and test it

build.gradle.kts

@@ -223,6 +223,7 @@ val coreLibProjects = listOf(
         ":kotlin-test:kotlin-test-common",
         ":kotlin-test:kotlin-test-jvm",
         ":kotlin-test:kotlin-test-junit",
+        ":kotlin-test:kotlin-test-junit5",
         ":kotlin-test:kotlin-test-testng",
         ":kotlin-test:kotlin-test-js",
         ":kotlin-reflect"

build.gradle.kts.182

@@ -222,6 +222,7 @@ val coreLibProjects = listOf(
         ":kotlin-test:kotlin-test-common",
         ":kotlin-test:kotlin-test-jvm",
         ":kotlin-test:kotlin-test-junit",
+        ":kotlin-test:kotlin-test-junit5",
         ":kotlin-test:kotlin-test-testng",
         ":kotlin-test:kotlin-test-js",
         ":kotlin-reflect"

libraries/kotlin.test/junit5/build.gradle

@@ -2,13 +2,11 @@ description = 'Kotlin Test JUnit 5'
 
 apply plugin: 'kotlin-platform-jvm'
 
-test {
-    useJUnitPlatform()
-}
-
 configureJvm6Project(project)
 configureDist(project)
 configurePublishing(project)
+ext.javaHome = JDK_18
+ext.jvmTarget = "1.8"
 
 project.ext["jpsLibraryPath"] = rootProject.distLibDir
 
@@ -35,6 +33,11 @@ dist {
     from (jar, sourcesJar)
 }
 
+tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile) {
+    kotlinOptions.jdkHome = JDK_18
+    kotlinOptions.jvmTarget = 1.8
+}
+
 compileKotlin {
     kotlinOptions.freeCompilerArgs = ["-Xallow-kotlin-package", "-module-name", project.name]
 }
@@ -42,3 +45,8 @@ compileKotlin {
 compileTestKotlin {
     kotlinOptions.freeCompilerArgs = ["-Xallow-kotlin-package"]
 }
+
+test {
+    useJUnitPlatform()
+    executable = "$JDK_18/bin/java"
+}