tree b0886b63bcdf8a34ac78e2ec492cc082af0b18a0
parent f1e905b0420782058464ef918e2c99c8b2d95445
author Damien Neil <dneil@google.com> 1565369414 -0700
committer Damien Neil <dneil@google.com> 1566338584 +0000

internal/impl: clean up obsolete ExtensionInfo fields/funcs

This is change 5/5 in a series of commits changing protoV1.ExtensionDesc
to directly implement protoreflect.ExtensionType.

1. [v2] Add protoimpl.ExtensionInfo as an alias for
   protoiface.ExtensionDescV1.

2. [v1] Update references to protoimpl.ExtensionInfo to use
   protoiface.ExtensionInfo.

3. [v2] Create protoimpl.ExtensionInfo (an alias to a new type in
   the impl package) and remove protoiface.ExtensionDescV1.

4. [v1] Remove unneeded explicit conversions between ExtensionDesc and
   ExtensionType (since the former now directly implements the latter).

5. [v2] Remove stub conversion functions.

Change-Id: I1fdfb18c481e72a362a6f9ee0e440f8f909790ca
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/189564
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>