In edge cases such as the following, sloppy-mode block-scoped function
hoisting is expected to occur:

  eval(`
    with({a: 1}) {
      function a() {}
    }
  `)

In this case, there should be the equivalent of a var declaration
outside of the eval, which gets set to the value of the local function
a when the body of the with is executed.

Previously, the way that var declarations are hoisted out of eval
meant that the assignment to that var was an ordinary DYNAMIC_GLOBAL
assignment. However, such a lookup mode meant that the object in the
with scope received the assignment!

This patch fixes that error by marking the assignments produced by
the sloppy mode block scoped function hoisting desugaring so as to
generate a different runtime call which skips with scopes.

Bug: chromium:720247, v8:5135
Change-Id: Ie36322ddc9ca848bf680163e8c016f50d4597748
Reviewed-on: https://chromium-review.googlesource.com/529230
Commit-Queue: Daniel Ehrenberg <littledan@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46116}