deprecate renderCss

src/generators/server-side-rendering/index.ts

@@ -155,7 +155,13 @@ export default function ssr(
 			map: ${cssMap ? stringify(cssMap.toString()) : 'null'}
 		};
 
+		var warned = false;
 		${name}.renderCss = function() {
+			if (!warned) {
+				console.error('Component.renderCss(...) is deprecated and will be removed in v2 — use Component.render(...).css instead');
+				warned = true;
+			}
+
 			var components = [];
 
 			${generator.stylesheet.hasStyles &&

test/js/samples/ssr-no-oncreate-etc/expected-bundle.js

@@ -39,7 +39,13 @@ SvelteComponent.css = {
 	map: null
 };
 
+var warned = false;
 SvelteComponent.renderCss = function() {
+	if (!warned) {
+		console.error('Component.renderCss(...) is deprecated and will be removed in v2 — use Component.render(...).css instead');
+		warned = true;
+	}
+
 	var components = [];
 
 	return {

test/js/samples/ssr-no-oncreate-etc/expected.js

@@ -41,7 +41,13 @@ SvelteComponent.css = {
 	map: null
 };
 
+var warned = false;
 SvelteComponent.renderCss = function() {
+	if (!warned) {
+		console.error('Component.renderCss(...) is deprecated and will be removed in v2 — use Component.render(...).css instead');
+		warned = true;
+	}
+
 	var components = [];
 
 	return {