Fix type checking of HTML element references through a component.

spec/examples/html_element

@@ -99,3 +99,25 @@ component Main {
     <div::base style="opacity:0;"/>
   }
 }
+-------------------------------------------------------------------------------
+enum Maybe(a) {
+  Nothing
+  Just(a)
+}
+
+component Test {
+  fun render : Html {
+    <div as test><{ "Hello" }></div>
+  }
+}
+
+component Main {
+  fun render : Html {
+    case test {
+      Maybe::Just(item) => { item.test "" }
+      Maybe::Nothing => ""
+    }
+
+    <Test as test/>
+  }
+}

src/type_checkers/access.cr

@@ -127,7 +127,8 @@ module Mint
                   memo[variable.value] = record.first
                 end
             when Ast::HtmlElement
-              memo[variable.value] = variable
+              lookups[node.field] = {variable, component}
+              return Type.new("Maybe", [Type.new("Dom.Element")] of Checkable) if node.field.value == variable.value
             end
 
             memo