Prevents some implementations (libstdc++ and libc++) from completely zeroing out the underlying
buffer and instead sets a single byte flag.
Eliminates unnecessary memsets.
Like the prior changes normalizing the inclusions within headers, this
tackles the cpp files of the RuntimeCommonB target, making these source
files consistent with their headers.
Makes use of the C++14 make_unique allocation function to allocate class
instances where applicable instead of a reset with a new operator within
it.
This doesn't touch cases where buffers are allocated, given make_unique
would zero-initialize them.