Fix some deprecations

src/main/java/org/spongepowered/asm/launch/platform/MixinConnectorManager.java

@@ -80,7 +80,7 @@ void loadConnectors() {
             }
 
             try {
-                IMixinConnector connector = connectorClass.newInstance();
+                IMixinConnector connector = connectorClass.getDeclaredConstructor().newInstance();
                 this.connectors.add(connector);
                 MixinConnectorManager.logger.info("Successfully loaded Mixin Connector [" + connectorClassName + "]");
             } catch (ReflectiveOperationException ex) {

src/main/java/org/spongepowered/asm/launch/platform/MixinContainer.java

@@ -70,7 +70,7 @@ public MixinContainer(MixinPlatformManager manager, IContainerHandle handle) {
                 String simpleName = clazz.getSimpleName();
 
                 MixinContainer.logger.debug("Instancing new {} for {}", simpleName, this.handle);
-                IMixinPlatformAgent agent = clazz.newInstance();
+                IMixinPlatformAgent agent = clazz.getDeclaredConstructor().newInstance();
 
                 AcceptResult acceptAction = agent.accept(manager, this.handle);
                 if (acceptAction == AcceptResult.ACCEPTED) {

src/main/java/org/spongepowered/asm/launch/platform/MixinPlatformManager.java

@@ -297,7 +297,6 @@ final void addTokenProvider(String provider) {
      */
     final void addConnector(String connectorClass) {
         this.connectors.addConnector(connectorClass);
-
     }
 
 }

src/main/java/org/spongepowered/asm/mixin/MixinEnvironment.java

@@ -1070,7 +1070,7 @@ public MixinEnvironment registerTokenProviderClass(String providerName) {
                 @SuppressWarnings("unchecked")
                 Class<? extends IEnvironmentTokenProvider> providerClass =
                         (Class<? extends IEnvironmentTokenProvider>)this.service.getClassProvider().findClass(providerName, true);
-                IEnvironmentTokenProvider provider = providerClass.newInstance();
+                IEnvironmentTokenProvider provider = providerClass.getDeclaredConstructor().newInstance();
                 this.registerTokenProvider(provider);
             } catch (Throwable th) {
                 MixinEnvironment.logger.error("Error instantiating " + providerName, th);

src/main/java/org/spongepowered/asm/mixin/transformer/PluginHandle.java

@@ -94,7 +94,7 @@ enum CompatibilityMode {
         if (!Strings.isNullOrEmpty(pluginClassName)) {
             try {
                 Class<?> pluginClass = service.getClassProvider().findClass(pluginClassName, true);
-                plugin = (IMixinConfigPlugin)pluginClass.newInstance();
+                plugin = (IMixinConfigPlugin)pluginClass.getDeclaredConstructor().newInstance();
             } catch (Throwable th) {
                 PluginHandle.logger.error("Error loading companion plugin class [{}] for mixin config [{}]. The plugin may be out of date: {}:{}",
                         pluginClassName, parent, th.getClass().getSimpleName(), th.getMessage(), th);

src/main/java/org/spongepowered/asm/service/MixinServiceAbstract.java

@@ -230,7 +230,7 @@ private List<IMixinPlatformServiceAgent> getServiceAgents() {
             try {
                 @SuppressWarnings("unchecked")
                 Class<IMixinPlatformAgent> agentClass = (Class<IMixinPlatformAgent>)this.getClassProvider().findClass(agentClassName, false);
-                IMixinPlatformAgent agent = agentClass.newInstance();
+                IMixinPlatformAgent agent = agentClass.getDeclaredConstructor().newInstance();
                 if (agent instanceof IMixinPlatformServiceAgent) {
                     this.serviceAgents.add((IMixinPlatformServiceAgent)agent);
                 }