[JVM] Load in-test defined classes by STDLIB_COMPILATION directive

In the current implementation, box test classloader loads
classes from `kotlin-stdlib.jar` even if we redefine it in the test
sources. We need to change this behavior, e.g., to test stdlib
compilation. However, implementation of such classloader consumes more
metaspace memory as we cannot share the stdlib classloader between
different test instances. Thus, we leave the old behavior by-default and
change it only if the test has `STDLIB_COMPILATION` directive.

compiler/testData/codegen/box/multiplatform/multiModule/stdlibClassRedefine.jvm_abi.txt

@@ -0,0 +1,27 @@
+MODULE main
+	CLASS kotlin/UIntArray.class
+		CLASS METADATA
+			K1
+				---
+			K2
+				equals(Ljava/lang/Object;)Z
+			K1
+				equals-impl([ILjava/lang/Object;)Z
+			K2
+				---
+			K1
+				---
+			K2
+				hashCode()I
+			K1
+				hashCode-impl([I)I
+			K2
+				---
+			K1
+				---
+			K2
+				toString()Ljava/lang/String;
+			K1
+				toString-impl([I)Ljava/lang/String;
+			K2
+				---

compiler/testData/codegen/box/multiplatform/multiModule/stdlibClassRedefine.kt

@@ -0,0 +1,28 @@
+// TARGET_BACKEND: JVM
+// WITH_STDLIB
+// LANGUAGE: +MultiPlatformProjects
+// JVM_ABI_K1_K2_DIFF: KT-67645
+// STDLIB_COMPILATION
+
+// MODULE: common
+// FILE: array.kt
+
+package kotlin
+
+@kotlin.jvm.JvmInline
+value class UIntArray(val delegate: IntArray) : Collection<UInt> {
+    override val size: Int
+        get() = delegate.size
+
+    override fun isEmpty(): Boolean = null!!
+    override fun iterator(): Iterator<UInt> = null!!
+    override fun containsAll(elements: Collection<UInt>): Boolean = null!!
+    override fun contains(element: UInt): Boolean = null!!
+    operator fun get(index: Int): Int = 42
+    operator fun set(index: Int, value: UInt) {}
+}
+
+// MODULE: main()()(common)
+// FILE: test.kt
+
+fun box(): String = if (UIntArray(intArrayOf(1))[0] == 42) "OK" else "Fail"

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/handlers/JvmBoxRunner.kt

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.test.directives.CodegenTestDirectives.ATTACH_DEBUGGE
 import org.jetbrains.kotlin.test.directives.CodegenTestDirectives.REQUIRES_SEPARATE_PROCESS
 import org.jetbrains.kotlin.test.directives.JvmEnvironmentConfigurationDirectives.JDK_KIND
 import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives.ENABLE_JVM_PREVIEW
+import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives.STDLIB_COMPILATION
 import org.jetbrains.kotlin.test.directives.model.singleOrZeroValue
 import org.jetbrains.kotlin.test.model.BinaryArtifacts
 import org.jetbrains.kotlin.test.model.DependencyKind
@@ -330,13 +331,24 @@ internal fun generatedTestClassLoader(
     classFileFactory: ClassFileFactory,
 ): GeneratedClassLoader {
     val configuration = testServices.compilerConfigurationProvider.getCompilerConfiguration(module)
-    val parentClassLoader = if (configuration[TEST_CONFIGURATION_KIND_KEY]?.withReflection == true) {
-        testServices.standardLibrariesPathProvider.getRuntimeAndReflectJarClassLoader()
+    val classpath = computeTestRuntimeClasspath(testServices, module)
+    if (STDLIB_COMPILATION in module.directives) {
+        val libPathProvider = testServices.standardLibrariesPathProvider
+        classpath += libPathProvider.runtimeJarForTests()
+        if (configuration[TEST_CONFIGURATION_KIND_KEY]?.withReflection == true) {
+            classpath += libPathProvider.reflectJarForTests()
+        }
+        classpath += libPathProvider.scriptRuntimeJarForTests()
+        classpath += libPathProvider.kotlinTestJarForTests()
+        return GeneratedClassLoader(classFileFactory, null, *(classpath.map { it.toURI().toURL() }.toTypedArray()))
     } else {
-        testServices.standardLibrariesPathProvider.getRuntimeJarClassLoader()
+        val parentClassLoader = if (configuration[TEST_CONFIGURATION_KIND_KEY]?.withReflection == true) {
+            testServices.standardLibrariesPathProvider.getRuntimeAndReflectJarClassLoader()
+        } else {
+            testServices.standardLibrariesPathProvider.getRuntimeJarClassLoader()
+        }
+        return GeneratedClassLoader(classFileFactory, parentClassLoader, *classpath.map { it.toURI().toURL() }.toTypedArray())
     }
-    val classpath = computeTestRuntimeClasspath(testServices, module)
-    return GeneratedClassLoader(classFileFactory, parentClassLoader, *classpath.map { it.toURI().toURL() }.toTypedArray())
 }
 
 private fun computeTestRuntimeClasspath(testServices: TestServices, rootModule: TestModule): MutableList<File> {