[PATCH] [libcxx] Initializer list support for MSVC

[Marshall Clow]

Regarding my "private" comment: I checked with MS, and the answer is "no". Even thought this is only called by compiler-generated code, the compiler still pays attention to the access permissions.

This is, of course, fixable in their compiler, and I will enter a DR for this vs MSVC. But that doesn't help us today.

http://reviews.llvm.org/D5127