[XRay][compiler-rt] Remove reliance on C++ ABI from BufferQueue

Summary:
This is part of the work to address http://llvm.org/PR32274.

We remove the calls to array-placement-new and array-delete. This allows
us to rely on the internal memory management provided by
sanitizer_common/sanitizer_internal_allocator.h.

Reviewers: eizan, kpw

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47695

llvm-svn: 333982