Fix type inferencing and syntax highlighting for method with extension property of same name

[eric-milles]

Consider the following:

class More {
  static int getLength(Pogo pogo) { 0 }
}

class Pogo {
  int length() { 1 }
}

use (More) {
  def pogo = new Pogo()
  println pogo.length()
  println pogo.length
}

"length" of length() is highlighted as an extension method; it is a standard instance method reference. The script prints "1 0" as expected, indicating that the runtime correctly selects the instance and property method respectively.

[eric-milles]