Fix return types of substitutions

Resolves issues with new strict checking introduced with
oracle/graal#7340

Author: zakkak

core/runtime/src/main/java/io/quarkus/runtime/graal/AwtImageIO.java

@@ -1,6 +1,6 @@
 package io.quarkus.runtime.graal;
 
-import java.awt.Graphics;
+import java.awt.GraphicsEnvironment;
 import java.awt.Toolkit;
 import java.util.Iterator;
 import java.util.function.BooleanSupplier;
@@ -41,7 +41,7 @@ public boolean getAsBoolean() {
 @TargetClass(className = "java.awt.GraphicsEnvironment", onlyWith = AwtImageIO.IsAWTAbsent.class)
 final class Target_java_awt_GraphicsEnvironment {
     @Substitute
-    public static Graphics getLocalGraphicsEnvironment() {
+    public static GraphicsEnvironment getLocalGraphicsEnvironment() {
         throw new UnsupportedOperationException(AwtImageIO.AWT_EXTENSION_HINT);
     }
 

extensions/resteasy-classic/rest-client/runtime/src/main/java/io/quarkus/restclient/runtime/graal/ClientHttpEngineBuilder43Replacement.java

@@ -4,6 +4,8 @@
 
 import javax.net.ssl.SSLContext;
 
+import org.jboss.resteasy.client.jaxrs.ClientHttpEngine;
+import org.jboss.resteasy.client.jaxrs.ClientHttpEngineBuilder;
 import org.jboss.resteasy.client.jaxrs.ResteasyClientBuilder;
 
 import com.oracle.svm.core.annotate.Alias;
@@ -16,13 +18,13 @@
  * {@code SSLContext.getInstance(SSLConnectionSocketFactory.TLS)} which will fail in native when the SSL has been disabled
  */
 @TargetClass(className = "org.jboss.resteasy.client.jaxrs.engines.ClientHttpEngineBuilder43")
-public final class ClientHttpEngineBuilder43Replacement {
+public final class ClientHttpEngineBuilder43Replacement implements ClientHttpEngineBuilder {
 
     @Alias
     private ResteasyClientBuilder that;
 
     @Substitute
-    public ClientHttpEngineBuilder43Replacement resteasyClientBuilder(ResteasyClientBuilder resteasyClientBuilder) {
+    public ClientHttpEngineBuilder resteasyClientBuilder(ResteasyClientBuilder resteasyClientBuilder) {
         that = resteasyClientBuilder;
         // make sure we only set a context if there is none or one wouldn't be created implicitly
         if ((that.getSSLContext() == null) && (that.getTrustStore() == null) && (that.getKeyStore() == null)) {
@@ -34,4 +36,10 @@ public ClientHttpEngineBuilder43Replacement resteasyClientBuilder(ResteasyClient
         }
         return this;
     }
+
+    /**
+     * Unused alias to implement the {@link ClientHttpEngineBuilder} interface
+     */
+    @Alias
+    public native ClientHttpEngine build();
 }