[PATCH] [libc++] Support Newlib as libc++'s C library (on ARM) [cmath part, part 1]

[JF Bastien]

Everything looks good but the presence of `math.cpp`.

================
Comment at: src/support/newlib/math.cpp:32
@@ +31,3 @@
+  return logb((double)x);
+}
+#endif
----------------
Wouldn't it be better to inline all of these into `math.h`?

http://reviews.llvm.org/D5419