Merge libc++/libc++abi license headers fixes into 3.8

[Eric Fiselier via cfe-commits]

Hi Hans,

I would like to merge the following commits into 3.8.

1. r258196 (libc++)
2. r258198 (libc++)
3. r258201 (libc++abi)

These commits simply add missing license headers.

@Marshall Can you please OK this?

/Eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20160119/3ca9bd4b/attachment.html>