This is meant to be a general place to list things that should be done "someday"

CXX Runtime Library Tasks
=========================
* Look into mirroring libsupc++'s typeinfo vtable layout when libsupc++/libstdc++
  is used as the runtime library.
* Investigate and document interoperability between libc++ and libstdc++ on
  linux. Do this for every supported c++ runtime library.

Atomic Related Tasks
====================
* future should use <atomic> for synchronization.

Test Suite Tasks
================
* Improve the quality and portability of the locale test data.
* Convert failure tests to use Clang Verify.

Misc Tasks
==========
* Find all sequences of >2 underscores and eradicate them.
* run clang-tidy on libc++
* Document the "conditionally-supported" bits of libc++