Add Kotlin extensions for bean registration and retrieval

Issue: SPR-15048

spring-context/src/test/kotlin/org/springframework/context/support/GenericApplicationContextExtensionTests.kt

@@ -0,0 +1,45 @@
+package org.springframework.context.support
+
+import org.junit.Assert.assertNotNull
+import org.junit.Test
+import org.springframework.context.support.GenericApplicationContextExtension.registerBean
+import org.springframework.beans.factory.BeanFactoryExtension.getBean
+import java.util.function.Supplier
+
+class GenericApplicationContextExtensionTests {
+
+	@Test
+	fun registerBeanWithClass() {
+		val context = GenericApplicationContext()
+		context.registerBean(BeanA::class)
+		context.refresh()
+		assertNotNull(context.getBean(BeanA::class))
+	}
+
+	@Test
+	fun registerBeanWithNameAndClass() {
+		val context = GenericApplicationContext()
+		context.registerBean("a", BeanA::class)
+		context.refresh()
+		assertNotNull(context.getBean("a"))
+	}
+
+	@Test
+	fun registerBeanWithSupplier() {
+		val context = GenericApplicationContext()
+		context.registerBean(Supplier { BeanA() })
+		context.refresh()
+		assertNotNull(context.getBean(BeanA::class))
+	}
+
+	@Test
+	fun registerBeanWithNameAndSupplier() {
+		val context = GenericApplicationContext()
+		context.registerBean("a",  Supplier { BeanA() })
+		context.refresh()
+		assertNotNull(context.getBean("a"))
+	}
+
+	internal class BeanA
+
+}