[box-tests] Tests on field init optimization

Added tests on all primitive types and a test when the field's type is an inline class

compiler/testData/codegen/box/secondaryConstructors/fieldInitializerOptimization_inlineClass.kt

@@ -0,0 +1,32 @@
+// IGNORE_BACKEND: JS
+// IGNORE_BACKEND: JS_IR
+// IGNORE_BACKEND: JS_IR_ES6
+// IGNORE_BACKEND: JVM
+// IGNORE_BACKEND: JVM_IR
+// IGNORE_BACKEND_FIR: JVM_IR
+
+open class Base {
+    open fun setup() {}
+    init { setup() }
+}
+
+inline class Z(val y: Int)
+
+class Derived : Base {
+    constructor() : super()
+    override fun setup() {
+        x = Z(1)
+    }
+
+    // Technically, this field initializer comes after the superclass
+    // constructor is called. However, we optimize away field initializers
+    // which set fields to their default value, which is why x ends up with
+    // value 1 after the constructor call.
+    var x = Z(0)
+}
+
+fun box(): String {
+    val d = Derived()
+    if (d.x.y != 1) return "fail"
+    return "OK"
+}