[PATCH] [libc++] Support Newlib as libc++'s C library [cmath part, part 2]

[JF Bastien]

>>! In D5420#10, @jroelofs wrote:
> @jfb do we lose anything by implementing these shims here, and then later pushing them into newlib?

There may be a combination of newlib + libc++ where the functions are defined twice, once in newlib and once in libc++. That seems like a bad idea.

http://reviews.llvm.org/D5420