defer doesnt work with block, break and await

[gabbhack]

Example

import asyncdispatch

proc foo() {.async.} =
  echo "foo"

proc main() {.async.} =
  block:
    defer: await foo()
    break

waitFor main()

Current Output

Expected Output

foo

$ nim -v
Nim Compiler Version 1.2.6 [Windows: amd64]
Compiled at 2020-07-29
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: bf320ed172f74f60fd274338e82bdc9ce3520dd9
active boot switches: -d:release

[Araq]

Other example program:

import asyncdispatch

proc f() {.async.} =
  while true:
    try:
      await sleepAsync(400)
      break
    finally:
      echo "finally handler"
      inc j

when isMainModule:
  waitFor f()