Overflows in Phobos

[Walter Bright via Digitalmars-d]

In poking around in Phobos, I found a number of cases like:

     https://github.com/dlang/phobos/pull/4655

where overflow is possible in calculating storage sizes. Since allocation 
normally happens in @trusted code, these are a safety/security hole.

When reviewing Phobos submissions, please check for this sort of thing.

     https://wiki.dlang.org/Get_involved#Review_pull_requests