[PATCH] These builtin functions set errno. Mark them accordingly.

[hfinkel at anl.gov]

Yep; *sigh*.

================
Comment at: include/clang/Basic/Builtins.def:165
@@ -166,1 +164,3 @@
+BUILTIN(__builtin_atanhf, "ff", "Fne")
+BUILTIN(__builtin_atanhl, "LdLd", "Fneqq")
 BUILTIN(__builtin_cbrt , "dd", "Fnc")
----------------
qq?

http://reviews.llvm.org/D3806