Provide equals/hashCode/toString for KType implementation

compiler/testData/codegen/boxWithJava/reflection/platformTypeNotEqualToKotlinType/J.java

@@ -0,0 +1,5 @@
+public class J {
+    public static String foo() {
+        return "";
+    }
+}

compiler/testData/codegen/boxWithJava/reflection/platformTypeNotEqualToKotlinType/K.kt

@@ -0,0 +1,11 @@
+import kotlin.test.assertNotEquals
+
+fun nonNullString(): String = ""
+fun nullableString(): String? = ""
+
+fun box(): String {
+    assertNotEquals(J::foo.returnType, ::nonNullString.returnType)
+    assertNotEquals(J::foo.returnType, ::nullableString.returnType)
+
+    return "OK"
+}

compiler/testData/codegen/boxWithJava/reflection/platformTypeToString/J.java

@@ -0,0 +1,11 @@
+import java.util.List;
+
+public class J {
+    public static String string() {
+        return "";
+    }
+
+    public static List<Object> list() {
+        return null;
+    }
+}

compiler/testData/codegen/boxWithJava/reflection/platformTypeToString/K.kt

@@ -0,0 +1,8 @@
+import kotlin.test.assertEquals
+
+fun box(): String {
+    assertEquals("kotlin.String!", J::string.returnType.toString())
+    assertEquals("kotlin.(Mutable)List<kotlin.Any!>!", J::list.returnType.toString())
+
+    return "OK"
+}