compiler: omit field name for embedded fields in reflection string

This matches the gc compiler.

The test case was sent for the master repo as
https://golang.org/cl/91138.

Fixes golang/go#23620

Change-Id: Ibdda1ae9b23eab61b1d35ec4f87638462a6ec1db
Reviewed-on: https://go-review.googlesource.com/91139
Reviewed-by: Than McIntosh <thanm@google.com>
2 files changed