FE MPP: add a test with expect value class B : interface with toString

Related to KT-54844

compiler/testData/diagnostics/tests/multiplatform/expectAbstractToString.kt

@@ -0,0 +1,23 @@
+// FIR_IDENTICAL
+// WITH_STDLIB
+// MODULE: m1-common
+// FILE: common.kt
+
+interface B {
+    override fun toString(): String
+}
+
+expect value class C(val s: String) : B
+
+expect value class D(val s: String) : B
+
+// MODULE: m1-jvm()()(m1-common)
+// FILE: jvm.kt
+
+@JvmInline
+actual value class C(actual val s: String) : B {
+    override fun toString(): String = s
+}
+
+@JvmInline
+actual value class D(actual val s: String) : B