create start anchors for each-blocks that need them

src/generators/dom/Block.js

@@ -5,10 +5,13 @@ export default class Block {
 	constructor ( options ) {
 		this.generator = options.generator;
 		this.name = options.name;
-		this.key = options.key;
 		this.expression = options.expression;
 		this.context = options.context;
 
+		// for keyed each blocks
+		this.key = options.key;
+		this.first = null;
+
 		this.contexts = options.contexts;
 		this.indexes = options.indexes;
 		this.contextDependencies = options.contextDependencies;
@@ -155,6 +158,10 @@ export default class Block {
 			properties.addBlock( `key: ${localKey},` );
 		}
 
+		if ( this.first ) {
+			properties.addBlock( `first: ${this.first},` );
+		}
+
 		if ( this.builders.mount.isEmpty() ) {
 			properties.addBlock( `mount: ${this.generator.helper( 'noop' )},` );
 		} else {

src/generators/dom/visitors/EachBlock.js

@@ -118,6 +118,13 @@ function keyed ( generator, block, state, node, snippet, { each_block, create_ea
 	const iteration = block.getUniqueName( `${each_block}_iteration` );
 	const _iterations = block.getUniqueName( `_${each_block}_iterations` );
 
+	if ( node.children[0] && node.children[0].type === 'Element' ) { // TODO or text/tag/raw
+		node._block.first = node.children[0]._state.parentNode; // TODO this is highly confusing
+	} else {
+		node._block.first = node._block.getUniqueName( 'first' );
+		node._block.addElement( node._block.first, `${generator.helper( 'createComment' )}()`, null, true );
+	}
+
 	block.builders.create.addBlock( deindent`
 		var ${lookup} = Object.create( null );