GCC: Scoped type name the same as name in outer scope

The compiler cannot handle a type name the same as the a type name
from an outer scope and leads to errors like the following one:

GCC(8.4.0) says

error: declaration of ‘using AcceptedVote = class performance_manager::
    voting::AcceptedVote<VoteImpl>’ [-fpermissive]
using AcceptedVote = AcceptedVote<VoteImpl>;
error: changes meaning of ‘AcceptedVote’ from ‘class performance_manager::
    voting::AcceptedVote<VoteImpl>’ [-fpermissive]
class AcceptedVote;

Bug: 819294
Change-Id: If344be8eff75cb9c5ca99b814f589595ed3c8bd1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2523201


Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Commit-Queue: Chris Hamilton <chrisha@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824908}