Disable warnings through comments.

src/compile/index.ts

@@ -11,13 +11,18 @@ function normalize_options(options: CompileOptions): CompileOptions {
 	let normalized = assign({ generate: 'dom', dev: false }, options);
 	const { onwarn } = normalized;
 
-	normalized.onwarn = onwarn
-		? (warning: Warning) => onwarn(warning, default_onwarn)
-		: default_onwarn;
+	normalized.onwarn = (warning: Warning) => {
+		if (!should_ignore(warning))
+			onwarn ? onwarn(warning, default_onwarn) : default_onwarn(warning)
+	}
 
 	return normalized;
 }
 
+function should_ignore({ start, code, frame }: Warning) {
+	return (new RegExp(`(?:${start.line - 1}:\\s*|${start.line}:[^\\n]+)<!--\\s*warn-disable\\s+${code}.*?-->`)).test(frame)
+}
+
 function default_onwarn({ start, message }: Warning) {
 	if (start) {
 		console.warn(`(${start.line}:${start.column}) – ${message}`);