Make Kotlin DSL class constructors internal

Closes gh-24059

spring-context/src/main/kotlin/org/springframework/context/support/BeanDefinitionDsl.kt

@@ -76,7 +76,7 @@ fun beans(init: BeanDefinitionDsl.() -> Unit) = BeanDefinitionDsl(init)
  * @author Sebastien Deleuze
  * @since 5.0
  */
-open class BeanDefinitionDsl(private val init: BeanDefinitionDsl.() -> Unit,
+open class BeanDefinitionDsl internal constructor (private val init: BeanDefinitionDsl.() -> Unit,
 							 private val condition: (ConfigurableEnvironment) -> Boolean = { true })
 	: ApplicationContextInitializer<GenericApplicationContext> {
 

spring-test/src/main/kotlin/org/springframework/test/web/servlet/MockHttpServletRequestDsl.kt

@@ -40,7 +40,7 @@ import javax.servlet.http.Cookie
  * @author Sebastien Deleuze
  * @since 5.2
  */
-open class MockHttpServletRequestDsl(private val builder: MockHttpServletRequestBuilder) {
+open class MockHttpServletRequestDsl internal constructor (private val builder: MockHttpServletRequestBuilder) {
 
 	/**
 	 * @see [MockHttpServletRequestBuilder.contextPath]

spring-test/src/main/kotlin/org/springframework/test/web/servlet/MockMultipartHttpServletRequestDsl.kt

@@ -27,7 +27,7 @@ import javax.servlet.http.Part
  * @author Sebastien Deleuze
  * @since 5.2
  */
-class MockMultipartHttpServletRequestDsl(private val builder: MockMultipartHttpServletRequestBuilder) : MockHttpServletRequestDsl(builder) {
+class MockMultipartHttpServletRequestDsl internal constructor (private val builder: MockMultipartHttpServletRequestBuilder) : MockHttpServletRequestDsl(builder) {
 
 	/**
 	 * @see [MockMultipartHttpServletRequestBuilder.file]

spring-test/src/main/kotlin/org/springframework/test/web/servlet/MockMvcResultHandlersDsl.kt

@@ -26,7 +26,7 @@ import java.io.Writer
  * @author Sebastien Deleuze
  * @since 5.2
  */
-class MockMvcResultHandlersDsl(private val actions: ResultActions) {
+class MockMvcResultHandlersDsl internal constructor (private val actions: ResultActions) {
 
 	/**
 	 * @see MockMvcResultHandlers.print

spring-test/src/main/kotlin/org/springframework/test/web/servlet/MockMvcResultMatchersDsl.kt

@@ -25,7 +25,7 @@ import org.springframework.test.web.servlet.result.*
  * @author Sebastien Deleuze
  * @since 5.2
  */
-class MockMvcResultMatchersDsl(private val actions: ResultActions) {
+class MockMvcResultMatchersDsl internal constructor (private val actions: ResultActions) {
 
 	/**
 	 * @see MockMvcResultMatchers.request

spring-test/src/main/kotlin/org/springframework/test/web/servlet/ResultActionsDsl.kt

@@ -8,7 +8,7 @@ import org.springframework.test.web.servlet.request.MockMvcRequestBuilders
  * @author Sebastien Deleuze
  * @since 5.2
  */
-class ResultActionsDsl(private val actions: ResultActions, private val mockMvc: MockMvc) {
+class ResultActionsDsl internal constructor (private val actions: ResultActions, private val mockMvc: MockMvc) {
 
 	/**
 	 * Provide access to [MockMvcResultMatchersDsl] Kotlin DSL.

spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/server/CoRouterFunctionDsl.kt

@@ -63,7 +63,7 @@ fun coRouter(routes: (CoRouterFunctionDsl.() -> Unit)) =
  * @author Sebastien Deleuze
  * @since 5.2
  */
-class CoRouterFunctionDsl(private val init: (CoRouterFunctionDsl.() -> Unit)) {
+class CoRouterFunctionDsl internal constructor (private val init: (CoRouterFunctionDsl.() -> Unit)) {
 
 	@PublishedApi
 	internal val builder = RouterFunctions.route()

spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/server/RouterFunctionDsl.kt

@@ -60,7 +60,7 @@ fun router(routes: RouterFunctionDsl.() -> Unit) = RouterFunctionDsl(routes).bui
  * @author Yevhenii Melnyk
  * @since 5.0
  */
-class RouterFunctionDsl(private val init: RouterFunctionDsl.() -> Unit) {
+class RouterFunctionDsl internal constructor (private val init: RouterFunctionDsl.() -> Unit) {
 
 	@PublishedApi
 	internal val builder = RouterFunctions.route()

spring-webmvc/src/main/kotlin/org/springframework/web/servlet/function/RouterFunctionDsl.kt

@@ -58,7 +58,7 @@ fun router(routes: (RouterFunctionDsl.() -> Unit)) = RouterFunctionDsl(routes).b
  * @author Sebastien Deleuze
  * @since 5.2
  */
-class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
+class RouterFunctionDsl internal constructor (private val init: (RouterFunctionDsl.() -> Unit)) {
 
 	@PublishedApi
 	internal val builder = RouterFunctions.route()