Back when mozalloc was a separate library, the xpcom glue code could not
use the infallible allocator API. But since bug 868814, that's not the
case anymore, so we can safely include mozalloc.h when XPCOM_GLUE is
set.

--HG--
extra : rebase_source : a8fbf8dc7020765d7287e2eb7ceaf41c99be8b18