Suggest new anonymous type syntax when absent

If an attempted anonymous type literal using the old syntax without the
'type' keyword appears in the program, a new error will be generated:
  Syntax error: Anonymous type literals must be written with the
  'type' keyword'.
The compiler will also generate a suggestion:
  Did you mean:
    1: method foo(x : type { bar -> String }) {
The previous error would display no knowledge of the anonymous type
change and suggest inserting type names or deleting tokens.