[PATCH] Portable flexible arrays instead of r12255

Hello,

    Trunk r12255 made Clang compiler happy by removing flexible nonPod[]
arrays. Unfortunately, it also moved shared memory items into local
memory (in some cases uninitialized). See the "[PATCH] Improve CLANG
support" thread.

The attached patch provides a Clang-friendly flexible array replacement
while keeping items in the shared memory (and using placement-new
initialization). The code may have become even less readable, but
hopefully more portable.

The changes passed build farm tests (except a couple of nodes with
Jenkins-related build problems unrelated to the code).

Thank you,

Alex.