compiler: mark generated struct/array types as incomparable

compiler: mark generated struct/array types as incomparable

    The recent change to generate type functions for more types with
    identity comparisons caused us to generate some unnecessary functions,
    and even caused a compiler crash on Solaris due to phase ordering.
    Avoid this by marking all generated and uncompared struct and array
    types as incomparable, so that we don't try to generate type functions
    for them.

    Reviewed-on: https://go-review.googlesource.com/35110

From-SVN: r244327