go/ast/astutil: revert support for Go 1.8 type aliases

This reverts commit 50193ec1c508c7b5714160a9c0979366fbbcabb4.

Reason for revert: aliases will not be part of Go 1.8

Change-Id: Idb3b74243eeb8dbeb2a2f4bd69a248c1dafa5348
Reviewed-on: https://go-review.googlesource.com/32835
Reviewed-by: Robert Griesemer <gri@golang.org>
1 file changed