Log Message:
Updated p5-Params-ValidationCompiler to 0.18.

0.18     2016-11-13

- Using coercions with positional parameters could cause a "Modification of a
  read-only value attempted" exception when the generated code tried to assign
  to elements of @_. This is now fixed by making a copy if any of the types
  have a coercion.

- Using Moose types with coercions in a positional params check would cause
  invalid code to be generated. This could also happen with Type::Tiny if
  either the type or a coercion could not be inlined.