Introduce complete DefaultGenerationContext constructor

Prior to this commit, it was possible to create a DefaultGenerationContext
based on a ClassNameGenerator and GeneratedFiles; however, there was no way
to create a DefaultGenerationContext that reused an existing RuntimeHints
instance which is necessary in certain use cases -- for example, in the
TestContext framework where multiple GenerationContexts are created
based on shared instances of GeneratedFiles and RuntimeHints.

This commit addresses this by introducing a public
DefaultGenerationContext(ClassNameGenerator,GeneratedFiles,RuntimeHints)
constructor.

spring-core/src/main/java/org/springframework/aot/generate/DefaultGenerationContext.java

@@ -32,6 +32,7 @@ import org.springframework.util.Assert;
  *
  * @author Phillip Webb
  * @author Stephane Nicoll
+ * @author Sam Brannen
  * @since 6.0
  */
 public class DefaultGenerationContext implements GenerationContext {
@@ -53,7 +54,21 @@ public class DefaultGenerationContext implements GenerationContext {
 	 * @param generatedFiles the generated files
 	 */
 	public DefaultGenerationContext(ClassNameGenerator classNameGenerator, GeneratedFiles generatedFiles) {
-		this(new GeneratedClasses(classNameGenerator), generatedFiles, new RuntimeHints());
+		this(classNameGenerator, generatedFiles, new RuntimeHints());
+	}
+
+	/**
+	 * Create a new {@link DefaultGenerationContext} instance backed by the
+	 * specified {@link ClassNameGenerator}, {@link GeneratedFiles}, and
+	 * {@link RuntimeHints}.
+	 * @param classNameGenerator the naming convention to use for generated
+	 * class names
+	 * @param generatedFiles the generated files
+	 * @param runtimeHints the runtime hints
+	 */
+	public DefaultGenerationContext(ClassNameGenerator classNameGenerator, GeneratedFiles generatedFiles,
+			RuntimeHints runtimeHints) {
+		this(new GeneratedClasses(classNameGenerator), generatedFiles, runtimeHints);
 	}
 
 	/**

spring-core/src/test/java/org/springframework/aot/generate/DefaultGenerationContextTests.java

@@ -66,8 +66,8 @@ class DefaultGenerationContextTests {
 	@Test
 	void createWhenGeneratedClassesIsNullThrowsException() {
 		assertThatIllegalArgumentException()
-				.isThrownBy(() -> new DefaultGenerationContext(null, this.generatedFiles,
-						this.runtimeHints))
+				.isThrownBy(() -> new DefaultGenerationContext((GeneratedClasses) null,
+						this.generatedFiles, this.runtimeHints))
 				.withMessage("'generatedClasses' must not be null");
 	}