Import of symbolic identifiers does not work

[odersky]

Example:

object P {
  def !#@ : Nothing = ???
}

object Test {
  import P.!#@
  def f = !#@
}

gives:

importSymbolic.scala:10: error: not found: !#@

  def f = !#@
          ^
one error found

The problem is that import selectors are untyped trees, and therefore do not undergo decoding of symbolic characters. The problem will be fixed once we move decoding into a late phase.