This also adds sources missing for PPC and x87, fixes a few
missing files in gyp due to wrong quotation and a few that
were simply not included.

The gn files are now authoritative, but the gcmole gyp and
gn source lists are enforced to match exactly.

This additional enforcement helped finding the bugs above
and will be removed when we deprecate the gyp files.

BUG=614645
NOTRY=true

Review-Url: https://codereview.chromium.org/2352103002
Cr-Commit-Position: refs/heads/master@{#39592}