`except:` clause always called during macro expansion

Consider the following example:

import macros

macro foo*(s: string{lit}) : expr =
  try:
    result = newLit(($s) & ": 42")
  except:
    result = newLit("ERROR")

echo foo("answer")

Executing this program results in "ERROR" although no exception has been raised.

A related problem is that a finally block within a macro is not called if the try block is exited by return (or break):

import macros

macro foo*(s: string{lit}) : expr =
  try:
    result = newLit(($s) & ": 42")
    return
  finally:
    echo "FINALLY"
    result = newLit("FINALLY")

echo foo("answer")

Compiling this code does not show "FINALLY" (and running the code does not so either).

[Araq]

This now works.