Context inside {{#each}} broken

[arggh]

Transpilation with Decaffeinate seems to have broken the context handling in {{#each}} loops. The context for {{b}} in all the iterations seems to be the last item in the array. This wasn't caught with any of the tests, which all still run succesfully.

For example, with a viewmodel:

Template.test.viewmodel({
  items: ['foo', 'bar', 'biz'],
  log(item) {
    console.log(item);
  }
});

...and a template:

<template name="test">
  {{#each items}}
     <button {{b "click: log(this)"}}>Log {{this}}</button>
  {{/each}}
</template>

...clicking on all of the buttons (Log fooLog barLog biz) always logs biz.

Pinging @ManuelDeLeon with high hopes 🤞

[ManuelDeLeon]

Check out what happens on currentContext (viewmodel.coffee line 532):

  currentContext = ->
    if currentView
      Blaze.getData(currentView)
    else
      Template.instance()?.data