JDK-8160310: HotSpot cannot be built with GCC 6

[Kim Barrett]

> On Jun 27, 2016, at 12:31 AM, David Holmes <david.holmes at oracle.com> wrote:
>  the missing spaces around "PTR_FORMAT" (how did they creep back in??).

We don’t have any mechanical check for it, and it’s easy to miss in a review.

I looked into using gcc’s -Wliteral-suffix to catch these, but it seemed that option was
being  ignored when not in C++11 or later mode.