Remove references to unused properties

[Rich-Harris]

Post-#1122 cleanup:

{{#each things as thing}}
  <p>{{thing}}</p>

  {{#if true}}
    <p>thing is unused</p>
  {{/if}}
{{/each}}

function create_main_fragment(component, state) {
  var each_anchor;

  var things = state.things;

  var each_blocks = [];

  for (var i = 0; i < things.length; i += 1) {
    each_blocks[i] = create_each_block(component, assign({}, state, {
-      thing: things[i],
-      thing_index: i
+      thing: things[i]
    }));
  }

  return {
    c: function create() {
      for (var i = 0; i < each_blocks.length; i += 1) {
        each_blocks[i].c();
      }

      each_anchor = createComment();
    },

    m: function mount(target, anchor) {
      for (var i = 0; i < each_blocks.length; i += 1) {
        each_blocks[i].m(target, anchor);
      }

      insertNode(each_anchor, target, anchor);
    },

    p: function update(changed, state) {
      var things = state.things;

      if (changed.things) {
        for (var i = 0; i < things.length; i += 1) {
          var each_context = assign({}, state, {
-            thing: things[i],
-            thing_index: i
+            thing: things[i]
          });

          if (each_blocks[i]) {
            each_blocks[i].p(changed, each_context);
          } else {
            each_blocks[i] = create_each_block(component, each_context);
            each_blocks[i].c();
            each_blocks[i].m(each_anchor.parentNode, each_anchor);
          }
        }

        for (; i < each_blocks.length; i += 1) {
          each_blocks[i].u();
          each_blocks[i].d();
        }
        each_blocks.length = things.length;
      }
    },

    u: function unmount() {
      for (var i = 0; i < each_blocks.length; i += 1) {
        each_blocks[i].u();
      }

      detachNode(each_anchor);
    },

    d: function destroy() {
      destroyEach(each_blocks);
    }
  };
}

// (1:0) {{#each things as thing}}
function create_each_block(component, state) {
-  var thing = state.thing, thing_index = state.thing_index;
+  var thing = state.thing;
  var p, text_value = thing, text, text_1, if_block_anchor;

  var if_block = (true) && create_if_block(component, state);

  return {
    c: function create() {
      p = createElement("p");
      text = createText(text_value);
      text_1 = createText("\n\n\t");
      if (if_block) if_block.c();
      if_block_anchor = createComment();
    },

    m: function mount(target, anchor) {
      insertNode(p, target, anchor);
      appendNode(text, p);
      insertNode(text_1, target, anchor);
      if (if_block) if_block.m(target, anchor);
      insertNode(if_block_anchor, target, anchor);
    },

    p: function update(changed, state) {
      thing = state.thing;
-      thing_index = state.thing_index;
      if ((changed.things) && text_value !== (text_value = thing)) {
        text.data = text_value;
      }

      if (true) {
        if (!if_block) {
          if_block = create_if_block(component, state);
          if_block.c();
          if_block.m(if_block_anchor.parentNode, if_block_anchor);
        }
      } else if (if_block) {
        if_block.u();
        if_block.d();
        if_block = null;
      }
    },

    u: function unmount() {
      detachNode(p);
      detachNode(text_1);
      if (if_block) if_block.u();
      detachNode(if_block_anchor);
    },

    d: function destroy() {
      if (if_block) if_block.d();
    }
  };
}

// (4:1) {{#if true}}
function create_if_block(component, state) {
-  var thing = state.thing, thing_index = state.thing_index;
+  var thing = state.thing;
  var p;

  return {
    c: function create() {
      p = createElement("p");
      p.textContent = "thing is unused";
    },

    m: function mount(target, anchor) {
      insertNode(p, target, anchor);
    },

-    p: function update(changed, state) {
-      thing = state.thing;
-      thing_index = state.thing_index;
-
-    },
+    p: noop,

    u: function unmount() {
      detachNode(p);
    },

    d: noop
  };
}

[Rich-Harris]

also, from #1220

A neater solution would determine that the click handler only needed the animal value and didn't need to get it in a convoluted way, so we could just pass that around instead of the array and the index

[Rich-Harris]

fixed in #1383