+++ This bug was initially created as a clone of Bug #711895 +++
Bug 711895's changes relating to -Wno-extended-offsetof are sub-optimal -- they don't break the build, but an unsupported option is passed to clang (and clang ignores it).
See bug 711895 comment 49 and 711895 comment 51 for details and a suggested fix.
Created attachment 607835 [details] [diff] [review]
This patch is from Irving Reid.
I found the docs for GCC 3.0.4 and -Werror was supported then, so I think we're safe to use it without any kind of check!
Bug 711895 was backed out due to i10n bustage. I'll fix this problem there when I reland.