Introduce -Xprogressive

compiler/testData/cli/jvm/progressive/dataClassOverridingCopy.kt

@@ -0,0 +1,5 @@
+interface WithCopy<T> {
+    fun copy(str: T): WithCopy<T>
+}
+
+data class Test(val str: String): WithCopy<String>

compiler/testData/cli/jvm/progressive/nonConstValueAsVarargInAnnotation.kt

@@ -0,0 +1,6 @@
+val nonConstArray = longArrayOf(0)
+
+annotation class Anno(vararg val value: Long)
+
+@Anno(value = nonConstArray)
+fun foo1() {}

compiler/testData/cli/jvm/progressive/valReassignmentViaBackingField.kt

@@ -0,0 +1,5 @@
+val my: Int = 1
+    get() {
+        field++
+        return field
+    }